Removing rear O2 sensor on 01-newer PCMs -- Things you should know

**Pure2sin** · 06-25-2013

You don't have to buy Tiny Tuner to use it. It's free.

**darkhorizon** · 06-25-2013

it will cycle the fuel dump test a few times per drive cycle. Roughly 3 times for an 01 during cruising.

One trick I have noticed works pretty good is to enable full time open loop, and you can even start lean cruising while removing the headache that is the rear o2 dump.

**kurupt305** · 07-17-2013

I have no clue what the hell I just read im new to the grand prix game got the 0420 code after putting an aftermarket header I cleared it with my obd2 scanner am I fine now or do I need the spark plug fouler other mod I have is intake no aftermarket pcm

**REDCRAPGP** · 07-17-2013

Smh

Do the spark plug fouler trick like I suggested. It's $7 for god sake! Or until you can have the code deleted from the PCM your going to throw that code that's what I suggested several times to do the trick.

**REDCRAPGP** · 07-17-2013

Originally Posted by REDCOMPG

Smh

Do the spark plug fouler trick like I suggested. It's $7 for god sake! Or until you can have the code deleted from the PCM your going to throw that code that's what I suggested several times to do the trick.

I'm going to post this here as well

**BillBoost37** · 07-18-2013

Even if you delete the code in the 01+ it'll dump fuel until it has a rear O2 not a simulator.

**REDCRAPGP** · 07-18-2013

I stand corrected

**KoldAsIce** · 03-31-2015

I know this post is majorly old BUT I was wondering if anyone has figured out exactly how to fix this either TT or DHP etc I just want a sure method to fix it! Thanks

**SgtMarshal** · 04-01-2015

the fix is to run a converter and a rear o2 sensor

**KoldAsIce** · 04-01-2015

I have a o2 but had to remove my cat cause it was bad but thanks for telling me your solution

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**Scottydoggs** · 04-01-2015

you can get a high flow cat for like 50 off ebay, then use one of then simulator deals to pull the o2 out of the pipe to trick it.

**KoldAsIce** · 04-01-2015

I know I can get a cat that's not the issue I'm just curious for the guys that don't have one and aren't gonna get one what they did to fix it.. everyone's solution couldn't have been to get a cat so I'm just curious I don't think I have the problem but like I said I'm curious to know

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**Reptile** · 04-01-2015

You don't have to run the converter, just leave the rear O2 in and turn off the catalyst codes.

**KoldAsIce** · 04-01-2015

I got that BUT for a certain few 01+ it runs diagnostics mode regardless of the codes being tuned out.. I don't think I have the problem BUT after I had to remove the cat my rear o2 isn't working anymore .4 to .5 and that's it.. I know the last time my rear o2 didn't work and I fixed it my mpg went up quite a bit so I'm just curious.. maybe a o2 sim might work but I have a good o2 in there right now

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**KoldAsIce** · 04-01-2015

BTW I'm getting a p0140 code

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**Reptile** · 04-01-2015

You're right, they will still run the diagnostic. The trick is keeping the light off for the p0420 code, but keeping the sensor active so that it detects the catalyst diagnostic. Once the rear O2 picks it up, it stops. The sensor is either bad, or the circuit is damaged. The P0140 is telling you that one of those two things are happening.

**KoldAsIce** · 04-01-2015

The o2 worked fine until I took the cat out but I will figure it out I guess

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**SgtMarshal** · 04-01-2015

I wasn't 100% sure the converter was necessary, but I thought it was so the rear o2 sensor could see a difference from the front o2 sensor.

**Reptile** · 04-01-2015

The only thing that the rear O2 is supposed to do, is detect when the converter is functioning properly or not, and in the case of some 01+ programming, a cat diagnostics code. It has no affect on how the front sensor functions. They are stand alone circuits. Turning a code to not reporting doesn't eliminate the fact that the sensor should still function, just not report a diagnostic problem.