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hello welcome to the site
the p0171 is a lean condition .
how many miles on the car ?
what service work has been done prior to this code appearing
ok please check to make sure the sensors don't have any oil on it from the filter.
if a filter has to much oil on it theirs a chance this will get on the sensor and alter the readings.
im 100% agree with you on the intake problem.
all your hoses are hooked up correctly ?
did k&n offer any help on this ?
the intake is the common thing here.
i could see if this was isolated to 1 bank but 2 is a concern.
well other then rechecking every hose and clamp i can amagine something with the air filter but i have seen some in the acuras cause intake issues.
with out me seen this first hand i have to go on the info you have given me.
was their a order on the hoses you removed on the stock intake?
mmm this is very odd.
i have seen issues on the cold air that drops down into the engine or bummer area.
did the intake temp sensor fit into the grommet ?
hmm now you have me in a tail spin.
this is a sensor that is on the actual intake piping.after the maf.
yes towards the engine. after the air filter leading to the throttle body
how did the acura turn out ?
Time to drive to autozone and buy part 1 minute
Time to change ignition coil 7 minutes
Expert advice .... Priceless !!
Thanks man... now fix my mazda speed 6 and I'll triple your price !!
thats great news glad the acura is running.
can you take a picture of the intake and all the hoses ect so i can get a birds eye view of the intake something just does not make sense here.
ok i will look this over.
the directions show a couple of hoses do you see these ?
the intake clamps look good.
can you run your hand around the intake piping and do you feel any fittings ?
and you cleaned the maf sensor was it dirty ?
ok well im not sure what else i can suggest on this.
im out of ideas on this.
i can re open this up to see if another expert has some ideas.
i have not see something so simple create so many problems.
i really don't see what else could be causing this besides the intake unless the shop broke something while installing the intake.
with out taking this all apart again and inspecting for damage or anything out of place.
New Expert here!
Welcome to Just Answer! My name isXXXXX will be happy to help you out and your 100% satisfaction is my goal. Please realize that all my answers are based solely on the info that you provide me with....
I have been following this thread and I would like to try and help you out. Sorry for so many questions but I would like to accurately diagnose your lean code. I just need a bit more info from you to point you in the right direction.
Do you have access to a scanner that can read live data?
How does the engine idle? How does the engine accelerate?
Lets take a look at the rpm in the freeze frame. I want to see if the code popped up at idle or when the engine rpm was up at higher rpms
Ok.. sounds good!
It might take the computerXXXXXcycles to light the MIL light when it sees this lean condition. THat is why is most likely popped up on the 2nd start up.
If in fact that it was at idle that this code was flagged, then chances are it is going to be an air or a vacuum leak. There is a difference between the two. A vacuum leak is after the throttle plate. An air leak is before the throttle plate but after the mass air flow sensor. Either way, there is a leak after the mass air flow sensor, the computer will see it as a lean condition and it will flag this code.
Again, look very carefully around the after market intake tube or snorkel for any place that air can enter that would not be accounted for by the mass air flow sensor.
If none is found, the best way to go about this diagnoses is to smoke check the intake for vacuum leaks with a smoke machine. THis makes it really easy to find air or vacuum leaks. However, before we get that far lets just get a good visual of the intake set up after the mass air flow sensor.
Also, you can check the mass air flow sensor grams per second on your scan tool.
The specs at idle is 3.6-3.8 for manual transmission and 3.8-4.0 for automatic transmission. At 2500 RPM's no load the specification is 10.5-11.2 for manual transmission and 10.6-11.4 for automatic transmission. If the readings are low the mass air flow sensor is bad or you have a vacuum leak.
In addition, check the fuel trims when the vehicle is at idle and at 2500 rpm driving down the road. If the fuel trims are high at idle and normal while driving at about 2500 rpm, my money is on either a vacuum or an air leak after the mass air flow sensor.
I will be looking forward to your reply!
Thats ok.. if you get a chance to get a scanner that can read live data, we can go that route... if not, lets just check the intake tube/snorkel for cracks or rips.
If you have a voltmeter, you should be able to get a volt reading from the mass air flow sensor.
You should be able to take a reading from the mass air flow sensor at idle and while snapping the throttle while in park. You don't have to be driving to do this.
If the voltage is low at idle, chances are the mass air flow sensor is bad or you have a vacuum leak.
Also, if you can try and get your hands on a scanner that can read live data, that would be very helpful as well.
Ok... sorry for the delay!
It is going to be either pin C or D. Here is an electrical diagram and a connector view of the mass air flow sensor.
Here is the testing for the mass air flow sensor straight from the book.
MASS AIR FLOW (MAF) SENSOR INSPECTION
Visually inspect for the following on the MAF/IAT sensor.Damage Cracks Bent terminals Terminal rust If any of the above are found, replace the MAF/IAT sensor. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION.)
MAF Rate and Load Value
NOTE: The scan tool shows the MAF rate and load value.
Circuit Open/Short Inspection
Disconnect the PCM connector (See PCM REMOVAL/INSTALLATION.)
Inspect the following harnesses for open or short circuit. (Continuity check).Open circuit
MAF/IAT sensor terminal A (harness-side) and main relay terminal C (harness-side) MAF/IAT sensor terminal B (harness-side) and PCM terminal 77 (harness-side) MAF/IAT sensor terminal C (harness-side) and PCM terminal 88 (harness-side)Short circuit
MAF/IAT sensor terminal A (harness-side) and body GND. MAF/IAT sensor terminal B (harness-side) and power supply. MAF/IAT sensor terminal C (harness-side) and power supply. MAF/IAT sensor terminal C (harness-side) and body GND.
Here are some more specs for your mass air flow sensor.
Key-On-Engine-Off Idle0.0-0.2 V 0.60-0.90 V
MAF Volts Grams Per Second of Air Flow0.34 V or 0.39 GPS0.39 V or 0.95 GPS0.50 V or 1.30 GPS0.60-0.90 V or 1.69-4.50 GPS1.00 V or 5.53 GPS1.96 V or 22.92 GPS3.90 V or 137.98 GPS
Typical Signal Values:Compare Mass Air Flow To Voltage;
Engine Off;- Key on engine off checks the zero air flow value, the voltage should be 0.0 to 0.2 volts. High sensor ground is the most likely cause of high signal voltage with the engine off.- If the voltage is wrong check B+, engine ground and sensor ground.
Engine Running;-Verify operation by comparing voltage to speed and MAF air flow values. These values vary with altitude and other operating conditions.
- If readings vary use voltage to air flow and 2 second wide open throttle test.
- Intake vacuum leaks will cause air flow values to be low because the air leak is not measured by the MAF sensor. Small leaks will show up more at idle than cruise because of the lower air flow at idle. Air leaks will cause long term fuel trim to be higher than normal.
I hear you loud and clear! Sometimes some vehicles can be very difficult to diagnose.
Lets keep our fingers crossed!
Please don't forget to hit the green accept button so that I may receive credit for the time that I have spent with you. In addition, bonuses and positive feedback are much appreciated!
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Car has been at the dealers for the last 3 days, now some $1,240 in Diag Fees later they can't figure it out. They want to fly in a specialist from Mazda to see if he will help. So I guess the saga continues.
What was done.
Replaced all hoses
Smoke checked, nothing found
replaced Cold Air Intake with factory box, etc...
Sorry for the delay!
Was the mass air flow sensor replaced with a factory part? Maybe it is this simple? I see these things go bad all the time! I have seen bad mass air flow sensors right out of the box!
Also, just an idea.. be sure the exhaust is not plugged and that the valve timing is dead on. I don't think this is the problem because the vehicle has plenty of power... but working on cars, I have seen stranger things.
I am just checking up on you. What have we found with the vehicle?