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ASEMaster35yrs, Chevy Technician
Category: Chevy
Satisfied Customers: 2095
Experience:  ASE Certified since 1972,Master Auto tech,Heavy Truck Tech ,chev dealer tech
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Camaro: a code 32 and may need to replace the EGR temperature switch

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HELP!!!! I'm throwing a code 32 and may need to replace the EGR temperature switch on my 1986 TPI Camaro. I can't find this part anywhere. I understand other cars and vans probably used this same part. Can anyone help me find one?



code 32 is for the bank 1 sensor 1 02sensor,voltage has nothing to do with an egr temp switch??


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Customer: replied 6 years ago.
I have a 1986 OBD1 system. I also have the HELM factory service manual. It verifies the code 32 is 'EGR SYSTEM FAILURE.' I used a scanner to read the code. It has nothing to do with the O2 sensor. Sorry, but your answer makes no sense in this case.
The EGR temp sensor is a huge problem and is also unavailable. The part went extinct in Feb. of 2009. Some guys fix them. I found one here: There's a tech article on the subject. Take the wire out of the EGR temp sensor and splice it into a vacuum operated switch that goes to ground when vacuum is applied, we splice this inline with the vacuum line to the EGR valve with a vacuum delay valve inline before it. This way when vacuum is applied to your EGR valve vacuum is also applied to the vacuum operated switch, the inline vacuum delay would simulate the warm up of the switch and then move the vacuum switch to the closed position grounding the terminal and sending a signal to the ECM telling it the valve is open and operating. Here is a link for the switch: . Or, you could just get it programmed out and have the EGR operate without it.Forum links

Code 32 is definitely EGR related for an OBD I car


DTC - 32 EGR system failure

Code 32- EGR circuit (fuel-injected models)


It is more likely the vacuum solenoid, but they also have been discontinued. I have learned that the vacuum solenoid for cadillac will interchange with yours if you need it. I found one place that says they have the EGR temp switch. You can find it at this link:



Forum links

Customer: replied 6 years ago.
I checked the EGR solenoid by putting a vacuum gauge at the control side of the solenoid. After letting the engine go into closed loop operation, I was able to move the throttle and watch the vacuum gauge go from having vacuum applied to the valve side to no vacuum applied. This tells me several things:

1. The ECM is working and controlling the solenoid. So all electrical harnesses and connections are good.

2. The solenoid is doing it's job by blocking and releasing vacuum. It also seems to have little bleed down. Also, I did buy probably the last available solenoid on the web a couple of years ago in anticipation of possibly needing one. So I do have a spare control solenoid available to me.

3. That all the vacuum lines are intact, not leaking and not blocked or partially blocked.

I then connected the EGR valve directly to a manifold port producing at least 10-15" Hg to check the valve's operation. I would've expected the engine to slow down or even stall at idle speed. It didn't. I may have a partially or completely inoperative valve. I was, however, unable to gain access to the EGR switch to see if it might be grounded all the time (it's buried under the intake plenum and the runners make it impossible for me to get to it). My main concern, of course, is being able to get another switch IF my mechanic finds the switch is bad. I understand that many of the emissions components on my car are discontinued. Which is a REAL problem as I have one more round of Connecticut's emissions testing to do next year before my car is finally exempt.

The problem with the link for '' is that their sensers are for a code 'H' engine. I have a code 'F' engine. It's the Tuned Port system, which uses different components.

The BIG problem here is the ECM MUST see a signal from that temperature switch at the right time or it'll set off the code 32. If my car is tested and there is a code 32 stored, they won't allow me to get a pass on the emissions and will want all kinds of money to try to repair it, which they may not be able to do.

Therefore, my botXXXXX XXXXXne question is: is there a same kind of 'F' code switch used on other vehicles that will screw into the base of the EGR valve that I can also use on my car. This is a real headache for me and is the primary reason why I'm annoying everyone here about it.


There is none that I know of other than possibly cadillac. You may have to make your own or have it programmed out.

Take the wire out of the EGR temp sensor and splice it into a vacuum operated switch that goes to ground when vacuum is applied, we splice this inline with the vacuum line to the EGR valve with a vacuum delay valve inline before it. This way when vacuum is applied to your EGR valve vacuum is also applied to the vacuum operated switch, the inline vacuum delay would simulate the warm up of the switch and then move the vacuum switch to the closed position grounding the terminal and sending a signal to the ECM telling it the valve is open and operating. Here is a link for the vacuum switch:


If you live in california, contact the BAR (Bureau of Automotive Repair). They should be able to tell you what to do in your case to pass emissions.

ASEMaster35yrs, Chevy Technician
Category: Chevy
Satisfied Customers: 2095
Experience: ASE Certified since 1972,Master Auto tech,Heavy Truck Tech ,chev dealer tech
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Customer: replied 6 years ago.
Thanks, ASEMaster35yrs.. I'll pass this information along to my mechanic when I get my car in and if he's unable to find the part. I live in Connecticut, and all they wish to do is just get cars like mine off the road. I can't have it programmed out until after I pass emissions for, hopefully, the last time.
Customer: replied 6 years ago.
I was able to find the connector pigtail for the EGR diagnostic temp switch and got 11vdc. So I now know the voltage the switch grounds to alert the ECM the valve is open is present, again, ruling out a bad ECM. Now I'm thinking the switch might be permenantly open.

Can I put that 12v sense line to the switch pigtail and wire it to chassis ground permenantly without damaging the ECM or causing the Code 32 to occur.

No, it will cause the computer to think the EGR is stuck open and throw the code 32.
Customer: replied 6 years ago.
Thanks. I appreciate the information very much. It sounds like a viable workaround for a unavailable sensor. I guess for now I think can either let off or accelerate slightly in order to keep throttle events to under 4 minutes to keep the 32 code from setting. If I understand how the ECM works properly....If I drive around town, I'm constantly accelerating and decelerating and changing throttle position and the code doesn't get set. I'm assuming it's because my throttle events are under 4 minutes in duration.

Thanks again!
Yes, that's one way to beat the emissions testing. What I have done with my car is that the ck engine light only comes on when I go on a long drive so when it's time for registration renewal and emissions test, I reset the computer and drive around town for 30 miles before taking it in for the test, then I'm good for another year or two. After resetting the computer you must have at least 30-50 miles for the test or you won't pass.
Customer: replied 6 years ago.
Thanks again for the info. I think next year is my last test. Connecticut has a 25 year limit. After that, I'm free to do what I want. Of course, there's no stopping the legislature from changing that. That's why when the vacuum switch is wired in (if the problem isn't the valve or passage), I'll do it so it can be easily returned to original condition for the next owner. The DMV here was down right unfriendly and so much as said I should get my old junker off the road if I couldn't get the emissions to work right. My old 'junker' can keep up with some pretty expensive sports cars and drives like it's new. In spite of it's 188Kmiles.
I don't think a friendly DMV exists so don't feel alone. It's the most dreaded place to go other than court. In California you can expect a minimum of 2 hours just to get to the window. It's worse than waiting inline at Magic Mountain or Disneyland. At least there, you'll have a good experience when you reach your destination. Good luck!
Customer: replied 6 years ago.
Gues what? It appears that NAPA may make a replacement for the EGR Diagnostic Temp Switch. I may've been too specific in my search using strick GM service nomenclature.

What do you think. It looks like the correct part. Just want a expert's opinion before getting too excited. They also make the EGR control solenoid and TPS that were all discontinued by GM. Just thought I'd pass this along in case it helps others solve similar problems.

I would go for it if you can get it. A while back I heard that they had it but when it came to ordering, it was back ordered. Perhaps they're in now. Go ahead and order them and see what happens. Let me know if they have them in stock or are still back ordered. When I tried that URL it said error.
Customer: replied 6 years ago.

I got the error, too. The URL might've changed. Anyway, if you get another error, Just select 1986 Camaro and type EGR in the search window. Scroll down the list of EGR parts and you'll see the 85 second delay switch.

The part # XXXXX: ECH TS7001 I would like to get your opinion if this part appears to be the part I'd need.

It looks like the one but sometimes the picture they show is not the actual part. I would call them to be sure. Call your local NAPA AUTO PARTS Store at 800-LET-NAPA(NNN) NNN-NNNN. Take your old switch down to your local NAPA store and compare for yourself. Type in your vin instead for more accurate application.
Customer: replied 6 years ago.
Thanks again. The shop I'm taking it to later this month will probably do all that. I know seeing a picture isn't always the way to go.
Customer: replied 6 years ago.
Hi ASEMaster35yrs:

Ok...I think I've truly determined the source of my code 32. Since I have a fully modified exhaust system, there may not be enough back pressure during part throttle cruise to fully open the EGR valve. I've therefore decided to go with the vacuum switch you mentioned. But, you also mention about a vacuum delay valve. My question to you is, which one should I get? I think the delay is supposed to be 85 seconds for simulate the temp switch warm-up period? I did find that NAPA does make replacement parts--valve and switch--but, they're special order items and not always available. And, I now believe that replacing both parts will not solve my Code 32. Essentially, if I were to replace my catylitic converter, this code would probably stop occuring. It started occuring after I swapped out my cat for a custom made straight pipe. I have headers, straight pipe AND a Flowmaster 3" exhaust system. And since the EGR valve uses exhaust back pressure to help open it along with the vacuum, my aftermarket system is probably providing too little back pressure to always completely open the valve.


Thanks again.
I had no idea you had modified the exhaust. You probably don't need the switch but you do need a catalytic converter. Your assumption is correct about the back pressure needed for the EGR valve to work. Buying the switch will not solve your problem.
Customer: replied 6 years ago.
Ok, least I know I'm on the right track. I should've mentioned about the modified exhaust system first. At the time, I didn't think it would matter. Now I see it does. My bad.

Just in case I'd like to try the switch, you did mention a vacuum delay valve is also needed. Which and what type of vac delay valve would be needed. I figure it might still work if the valve isn't opening all the way and the temp switch isn't getting enough heat to ground the ECM sense line.

Meantime, at least I now know exactly what is going on.


UPDATE: I just talked to the shop and they said my EGR valve is indeed bad. The other shop said it was working. They're getting me a after market valve. So this may, indeed, solve my problem.

I believe I already sent you a link for the vacuum switch. Standard Motor VACUUM OPERATED SWITCH MC-VOS3. .


But the switch will not help without back pressure.

Customer: replied 6 years ago.
Indeed you did....I just wasn't sure if there was also supposed to be another part to delay the switch's operation to simulate the time needed for the EGR diag. temp sensor to heat up. So I'm assuming this switch has some sort of setable delay timer?

At this point, there's no sense in doing anything now. Especially since the egr valve is actually bad. I had a feeling this was the case early on because one of the first things I did was to connect the egr valve directly to a vacuum port. The engine idle speed didn't change. I expected it to either drop or the engine to stall. Nothing happened. I still didn't think I knew enough so I had someone else I trusted to check the valve and it turns out they were wrong about it being ok. So THEY didn't know enough.

In fact, there may just be enough back pressure to operate the egr valve...I'll be interested to see how the engine runs with the new valve. I was getting some backfiring when the engine was running cold. I might also get better performance AND be able to use 87 octane fuel instead of the 89 I was running.

Thanks again for the help.


The EGR does not operate when cold, nor when below 1500 RPM's. If it is stuck open, you will have a problem when cold or below 1500 rpm. Replacing the EGR may solve your problem if it was stuck open. Read the following to better how to understand how your EGR system works.


How the EGR valve works

Early EGR systems are made up of a vacuum-operated valve ( EGR valve ) that admits exhaust gas into the intake manifold, a hose that is connected to a carburetor port above the throttle plate and a thermostatic vacuum switch ( TVS ) spliced into a pipe that is threaded into the coolant passage near the thermostat. The TVS detects the operating temperature of the engine.

At idle, the throttle plate blocks the vacuum port so no vacuum reaches the EGR valve and it remains closed. As you accelerate, the throttle uncovers the port in the carburetor or the throttle body, the vacuum signal reaches the EGR valve and slowly opens it, allowing exhaust gases to circulate into the intake manifold.

Since the exhaust gas causes a rough idle and stalling when the engine is cold, the TVS only allows vacuum to the EGR valve when the engine is at normal operating temperature.

Also, when the pedal is pushed all the way to the floor under acceleration, there is very little vacuum available, resulting in very little mixture dilution that would interfere with power output.


The EGR valve on early carbureted engines without computer controls acts solely in response to the temperature and venturi vacuum characteristics of the engine.


The EGR valve on engines with electronic fuel injection systems is controlled by the engine control computer ( ECM ) . EGR valves on computerized vehicles normally have a computer controlled solenoid in line between the valve and the vacuum source. They also often have an EGR position sensor that informs the computer what position the EGR valve is in.


There are 2 common types of EGR valves: Ported vacuum EGR valves and backpressure EGR valves.

The valve we described earlier is the ported EGR valve, besides this type; there are basically 2 types of backpressure EGR valves. The most common type is the positive backpressure valve, the other one is the negative backpressure valve.

It is important to know the difference between positive and negative backpressure valves because they work differently and they are tested differently also.


Positive backpressure EGR valve:

This type o valve is used largely on domestic models. It uses exhaust pressure to regulate the EGR flow through a vacuum control valve. The stem of the EGR valve is hollow and allows backpressure to enter at the bottom of the diaphragm. When sufficient exhaust backpressure is present, the diaphragm moves up and closes off the control valve, allowing the full vacuum signal to be applied to the upper portion of the EGR diaphragm. This opens the valve and allows recirculation to occur during heavy loads.

Be careful not to incorrectly diagnose this type of EGR valve. Because backpressure must be present to close the bleed hole, it is not possible to operate the EGR valve with a vacuum pump at idle or with the engine off. The valve is acting correctly when it refuses to move when vacuum is applied or it refuses to hold vacuum. Remember that anything that changes the pressure in the exhaust stream will disturb the calibration of the backpressure system including after market exhaust systems, headers and even clogged catalytic converters.

To distinguish this valve, turn it upside down and note the pattern of the diaphragm plate. Positive backpressure valves have slightly raised X-shaped rib. Negative backpressure EGR valves are raised considerably higher. On some GM EGR valves, the only way to distinguish each type is by a letter next to the date code and part number. N means negative and P means positive.


Negative backpressure EGR valve:

In this system, the bleed hole is normally closed when exhaust backpressure drops, the bleed valve opens and reduces the vacuum above the diaphragm, cutting the vacuum to the EGR valve. The negative backpressure EGR valve is similar to the positive backpressure EGR valve but operates in the opposite way. This type of valve is typically used on engines that have less than normal backpressure such as high performance vehicles with free flowing mufflers and large diameter exhaust systems.

Customer: replied 6 years ago.
Yep....I know. The egr doesn't work under non cruise throttle and open loop situations. Only part throttle constant throttle in closed loop at mostly highway speeds. My car does about 45 mph at 1500 rpm. I think thats about the speed they run on the test dyno but probably in 4rth rather than the 5th OD gear. I have a 3.73:1 rear axle.


Are you aware that it is illegal to remove your catalytic converter?

$2500 fine for violation for you and the installation agency no more than $25,000..

Read this:


When going in for a vehicle inspection, I would be more worried about that, than code 32. Not passing inspection would be the least of your problems then.

In all states, they do a visual inspection.

You will not pass inspection if you have modified your emissions system and will be required to replace any and all parts missing at your cost besides the fine.

Customer: replied 6 years ago.
I'm aware of this. I have it set up where it takes only 15 minutes to swap out the cat. I I don't go to emissions without it installed. I have both a Magnaflow cat and the stock cat (it only has about 10K on it). If things get sticky, I can always get the Magnaflow back on quickly. So they'll always see the cat installed. If I went down w/o the cat on, they'd just fail me for inspection. I don't think they'd purposely try to get me into trouble. But, there's always some risk. I just feel it's fairly minimal. I even kept the AIR pump connected (my headers have the AIR tubes and O2 bung) and kept the original cast iron exhaust manifolds, just in case. After 25 years, CT stops checking emissions. So I should have just next year to get through then that should be it.

My other car, which is a Mazda3, will remain completely stock.

Thanks for the info.
I would keep those parts around, just in case. They are changing laws all the time. There was a time when 25 years was enough, but then they revised the law lately to any car before 1976 was exempt but after that date they must comply. From what you told me, replacing your EGR valve should do the trick and you won't need the switch.
Customer: replied 6 years ago.
I will. I've NEVER put any trust in politicians. So these parts are sitting in my garage and basement....just in case...

Also, the car is for sale, so I want to keep these parts for the next owner, just in case they need to get them all re-installed. One of the biggest mistakes I've read about is when cars are modified and the OEM parts are tossed. Then the laws change, like you said, and the owners are suddenly scrambling to re-collect those very expensive emission parts. At least I saved mine.

BTW, here's a link to picts of my car:

Thanks again,

Customer: replied 6 years ago.
Thanks! Actually, what I'd really like to get is a 2004 ZO6 Corvette. I've always wanted a 'vette since I was a kid. And the '04 has the most potent variant of the 350 before they went to the 427 in 2006. I've seen them for less than the price of a new ZL1. Though the vette is 405 hp compared to the ZL1's 550, the 'vette is about 600 lbs lighter and is a true dedicated sports car. The new Camaros are too sedan like for my tastes. I also sat inside one and it was like sitting inside a troop transporter. I was actually getting a little thing about the iroc is that it's a dedicated sports car platform. It was probably derived from the old X body, but, no other car used it the same platform except for the Firebird. The new Camaro is a G8 platform. My friend has a Pontiac G8...beautiful car, but it's a 4000lb 4 door family sedan. Too big and too heavy for my tastes.

Also, the smaller engine will get much better mileage. I've seen 2004's for about $30K with under 40kmiles. Add on a $5500 Magnacharger or Whipple Charger and it'll be a monster. But, honestly, 400hp in a 3200lb car is enough for me. And the handling is supposed to be amazing. Very Ferrari like. It's the take off of their CR-5 le mans winning race car.


The way things are with the economy, I may not be able to sell the car anyway.
The only thing bad about a corvette is the insurance is higher but it probably would balance out being that it is a 2004. I have 400hp in my 64 1/2 mustang that weighs 2800 lbs.
Customer: replied 6 years ago.
Actually, I can get the Z06 insured through Grundy. I'm using them for the iroc and it's saving me nearly $1000/year compared to my normal insurance carrier. They charge me $158 for the year for a agreed value of $8500. But, I have limited use with a number of restrictions. Which is fine as I only drive it on nice days, etc. It spends most of it's time in the garage, anyway.

400hp in a old 'stang like that? Did you have to have any body reinforcing done? Those cars were pretty lightly built. That must be a real rush when you mash the pedal with that level of power. That car is a hugely saught after classic for sure.
The only thing I had to do to it was put 390 mustang axles in it because I twisted the originals in half. It came stock with the high performance engine, rally pack & top loader close ratio 4-speed. I beefed it up when I rebuilt it after 150,000 miles. The biggest increase in power was what I did to the heads. I ported out the exhaust ports 1/4" and intake 1/8", installed chevy 1.94 intakes and 1.60 exhaust valves and cc'd the combustion chambers, brass valve guides, screw-in rocker studs, heavy duty valve springs and comp cam with 294 duration and 5.15 lift. I had to fly cut the valve reliefs on the pistons to accomodate the bigger valves. The block has been lined bored and the engine balanced. It's a 289 bored .030 over and looks completely stock except for the performer intake & headers and duel feed 750cfm holley 3310. I did all the work myself except for the machining & balancing. What's really weird is that before the work, I was getting 10mpg and after all the upgrades I get 15mpg and it turns 10,000 rpm's and holds together just fine. I have no p/s and no other add-ons to rob power. I come out of third at 100mph. In one city block, I had it up to 100mph and back to a stop for the traffic light, never got to 4th that time. I have traction bars in the rear with 265/50R-14 tires. When I take my wife for a drive, she is pinned to the seat and can't touch the dash. It's like riding on Montesuma's Revenge at Knott's.
Customer: replied 6 years ago.
Not surprised about breaking the axles /w that kind of power. I remember my grandmother talking about how my grandfather's auto store sold more axles than most anything else. Back then (in the 30s), axles would break only engines with about 30-50 hp or so. Not to mention all the hard jostling from the rough roads at that time.

I think the Tremec TK500 I have in the iroc is based off the Ford top loader 4 speed transmission. It's supposed to be a fairly stout piece…I hope. It only makes sense to do a complete rebuild to higher performance standards if you're planning on keeping it for a long time. I believe the factories now port and polish their heads and intake manifolds. It's funny how they've adapted to many of the old 'hot rodder' techniques to get more power. I remember the 289 in the original Mustangs. They were pretty nice engines to begin with at that time. Also not surprised you got better mileage. Probably due to less pumping losses from the freer flowing intake and exhaust work. It's great to be able to do that level of mechanical work. I only did surface mechanics with my cars. Occasional bolt ons, etc. However, when it comes to the electrical stuff, thats my department. I leave the heavy mechanical stuff to the pros like yourself.

One neat thing, though. If one buys a new Z06, there is a option where you fly to detroit and build the engine yourself under the guidance of the factory engine team. Talk about a great experience that would be. I'd love to build my own LS 427. That would be incredible fun.

You could probably tape a $20 bill to your dash board and challenge people to try to take it when you're under full acceleration!! LOL!

My engine, being a TPI, and low compression (9.5:1) limit the power level of that particular mill. If I were to just add the aluminum heads with roller cam, I could get a instant 25 hp increase. The other improvement would be to remove the TPI system and swap in the E-Z Fast Carb system. Use maybe a dual plane intake manifold with 4150 throttle body config., manual distributor and have a single 4 barrel 4 point TB injection system /w wide band O2 sensor that will allow up to 1000 CFM of flow. Or, just swap out the L98 5.7 for a LS type engine with the later high flow intake manifold. Lots of options and lots of $$$$$ for any of them, unfortunately. I recently had the compression checked on the engine and it was 150-160 psi across all cylinders. No more than a 7.75% variation between adjacent bores. So though my engine has 150Kmiles on it, it still runs like new. For now, I guess I'll just be satisfied with 220 bhp and 320 lb-ft at the back wheels, as tested back in 2004 /w 89 octane fuel. With 3.73 gears, it can still be reasonably entertaining. At least it's a WHOLE lot better than having the 5.0l which was not a great engine. The extra 45 cubic inches and Corvette heads make a big difference.
Power costs money especially if you have to have someone else do the work. My best friend had a 1963 stingray split window with the 360hp 327. He took that engine out and dropped in a 1969 L88 rat motor 427 550hp. He taped a $100 bill to the dash and challenged me to grab it when he took off. I could not move an inch to even touch it. He had to sell it when he got drafted for viet nam. What a shame!
Customer: replied 6 years ago.
Hmmm...Inflation, eh? Wow, $100! That's quite the challenge. Those rat engines have quite the reputation. It's amazing what they have to do today to get that kind of power out of a engine...what with all the smog regulations and mileage restrictions, etc.

Just got a call from the dealership. They actually found a factory GM EGR valve. I said they must be rare as hen's teeth. The after market one they ordered apparently didn't work out. My guess it was missing the threaded hole at the base for the temp sensor switch. Also found out my reverse lights aren't working. This will be a fairly large invoice after they're done. Oh well, at least I'm saving on the insurance so I can spend it on