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Ron Z.
Ron Z., - Toyota Tech -
Category: Toyota
Satisfied Customers: 16041
Experience:  18+yrs experience. State Inspector and Toyota Diagnostics
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1998 Toyota Camry: V6..The check engine light stays..meter..O2 sensor

Resolved Question:

I have a 1998 Toyota Camry V6, The check engine light stays on so that it won't pass inspection. The meter indicated replace the O2 sensor which we did. It still indicates that there are 3 sensors out.
Submitted: 4 years ago.
Category: Toyota
Expert:  Ron Z. replied 4 years ago.

Can you give me the actual "p-code" that was retrieved that led you to replace an O2 sensor?


Customer: replied 4 years ago.
I don't have the code. Two mechanics checked the car with different meters and both showed the same code calling for replacement of the O2 sensor ehich was done, but made no difference.
Expert:  Ron Z. replied 4 years ago.
Ok, the only problem with that, is there is more than one oxygen sensor on this vehicle, and i'd like to know which sensor (location on engine) that was replaced, and if I had a "p-code" I could verify the correct sensor was replaced. Toyota is fairly good at recognizing when a sensor is replaced, and if the Check Engine light is STILL on, the repair, more than likely, was not made correctly.
Customer: replied 4 years ago.
The mechanic says the sensor replaced was P0135, the sensor at the front of the engine, which was the one indicated on the testing meter.
Expert:  Ron Z. replied 4 years ago.

ok- here's the problem. P0135 is a problem in the Internal Heater for the A/F Sensor (aka Oxygen Sensor) for Bank1 Sensor1. The PCM uses this internal heater to get the sensor to normal operating temps within a matter of seconds on cold starts. This sensor is located mounted to the exhaust manifold closest to the firewall. Long story short- the wrong sensor was replaced.


Customer: replied 4 years ago.

Then, what is the number for the correct sensor and where is it located?

And if this is the wrong sensor, why did that number show up on the meter?

Expert:  Ron Z. replied 4 years ago.
P0135 is Bank1 Sensor1, there is no getting around that. The sensor in the front of the engine is Bank2 (as shown in image above), The botXXXXX XXXXXne is- the wrong sensor was replaced. I have no idea why your mechanic just "assumed" it was the front sensor. I cannot answer that. The "meter" doesn't lie, and the OBDII code of P0135 is universal for just about every make, model and 6-8 cylinder engine on the planet. Heater malfunction in Bank1 Sensor1. Again, as shown in the image above, the CORRECT sensor to be replaced with a P0135 is Bank1 Sensor1 (in the exhaust manifold, closest to the firewall). As for the part number- I will need to know if it has Federal or California emission.
Customer: replied 4 years ago.

The diagram does not look like my engine. I have a 1998 Camry with a

V6 3000 Four Cam 24. The mechanic says he thinks it has only 2 O2 sensors.


Since the car has always been in New York, I assume it has Federal emission.

Expert:  Ron Z. replied 4 years ago.
Ok- the V6 Camry has 4 Oxygen Sensors, as shown above. Even the 4-cylinder has 3. The diagram above is straight from Toyota and covers all their 1MZ-FE motors (which covers 1994- 2003 models) . Just becuase the vehicle has never left New York does not mean it cannot have California emissions. There is a sticker under the hood that will say wether it's Fed or Cali. I think we're turning a mole hill into a mountain here because for some odd reason, we're not agreeing as to what the problem is. If you'll notice above, i've had another Expert "Agree" with my answer. This is actually an extremely common Toyota fail item, and we're really making this harder than it needs to be.
Customer: replied 4 years ago.

The car has Federal emissions, it says "not for use in California." Please send the correct part number. Also the number for B2, S1 which, I assume is the one that was replaced incorrectly.

This is actually the second time they've replaced the O2 sensor with no results.

I sure hope it works this time.

Expert:  Ron Z. replied 4 years ago.

Well, when you have a P0135, and replace the wrong sensor, unfortunately, you will not see results. Had the correct sensor been replaced the first time, you would have been past this a long time ago. With all due respect- if your mechanic doesn't know where "Bank 1" is on a V6 Toyota, or that a P0135 is a code for Bank1 Sensor1, or doesn't "know" there's more than 2 Oxygen Sensors on a V6 engine - it may be time to find a new mechanic. He's going to cost you a TON of money in the future with mis-diagnosed problems, and replacing parts at random. Like I say- this is an extremely common fail item, and there's no reason the correct diagnosis and repair shouldn't have been made the first time.


As for the part#- I onyl have access to Toyota OEM Part #'s, however, if you take the OEM part number to any local "aftermarktet" parts store, they can "cross over" the OEM to whatever aftermarket brand they sell (I would recommend a "better quality" parts store, like say, NAPA as opposed to AutoZone-you get what you pay for!). You can also order the part by name "Bank1 Sensor1 without Cali emissions" and you'll get the correct part. On the Federal model, the part for Bank1 and 2 are the same.


1998 Toyota Camry LE Sedan V6-3.0L (1MZ-FE)

PartOEM PartPrice
Oxygen Sensor
Oxygen Sensor

Edited by DriveFast1971 on 12/22/2010 at 6:44 PM EST
Ron Z., - Toyota Tech -
Category: Toyota
Satisfied Customers: 16041
Experience: 18+yrs experience. State Inspector and Toyota Diagnostics
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