P0131 code = HULK SMASH

[clewis05]

Ok gents for starters I drive a 99 Z28 M6. mods: pacesetter LT, 3" Y pipe, lid box mod, k&n air filter slp bellow, ls7 clutch assembly, short throw shifter, rear O2 deleted, TunebyFrost, BMR LCA and pan hard bar. For the most part vehicle is stock. I've been throwing this code for awhile among others. I've fixed everything but this damn P0131. The MAF is new and the O2 is new. I've swapped O2 trick and problem stayed on driver side. I've exhausted all options. Does anyone have any ideas what is causing this problem. It's causing my car to dump more fuel and has slight hesitation at first start. How can I find the problem. Do I have a ground issue some where? Please help. Thanks. Chris

[0rion]

I would say you either have an exhaust leak on that side pre-O2 or possibly a bad injector. What about the a.i.r. or egr systems? On the car still? Anywhere you might be getting air into the exhaust stream I would look at. After that I would swap injectors side to side and see if it follows.

[pajeff02]

This is a comprehensive P0131 diagnostic:

- Faulty Front Heated Oxygen Sensor Bank 1
- Front Heated Oxygen Sensor Bank 1 harness is open or shorted
- Front Heated Oxygen Sensor Bank 1 circuit poor electrical connection
- Inappropriate fuel pressure
- Faulty fuel injectors
- Intake air leaks may be faulty
- Exhaust gas leaks

[clewis05]

I've already tested the injectors. They are working fine. I have both systems on my car still. I want to tear it all out just don't feel with hassling with those codes yet. I replaced all intake gaskets and checked the vacuum I'm spot on there.

[2002ssslp]

I have seen this before and it was the fuel injectors. What type of fuel do you use ? Do you use any additives ? Did you recently take the fuel rails off ? Did you check the fuel pressure ? When was the last time you replaced your fuel filter ?

[clewis05]

I use 91 octane no additives. I did have the fuel rails off recently to replace the intake gaskets but it was doing this before I had them off. I have the gauge on the fuel rail and it's got the right pressure. I haven't change the fuel filter in about a year. Figured if I'm getting the right pressure then the filter should still be good.

[0rion]

what O2's did you use? Went through this on my brother's car and 1 of the O2's we bought was bad out of the box. Maybe try switching those side to side to make sure.

[clewis05]

I got the denso one for a vette. This is the second O2. I've already swapped them side to side and the code stayed on the driver side

[pajeff02]

Did you reset the SES after making the swap? It's easy to check the sensors for proper heater function and such, just need the pinouts.

[0rion]

denso sensors suck.....that's the same one that we had bad right out of the box. If you're positive the sensor is good I would next look at the harness. Seems to me you're missing something because it can only be a few things causing that code.

[RONS98TA]

I think the wire harness is bad, or there is a burnt or broken wire to the sensor/harness. Maybe the wire was touching the exhaust and got burnt. You have already ruled out a bad sensor because you switched them and the problem stayed on the same side. I would try ohming out the wires to the sensor.

[0rion]

when you did long tubes did you buy O2 extensions or make your own extension?

[clewis05]

Ya I cleared out the codes when I did it

[clewis05]

I'm going to Ohm the wires and see what each say. I had extensions on them but the one on the driver said melted on the LT so I got the longer corvette O2s.

[pajeff02]

The Bosch 13111's have run flawlessly in our car for about 4-5 years now.

[clewis05]

The Bosch 13111's have run flawlessly in our car for about 4-5 years now.

I read so many mixed reviews with those. I'm hesitant to try them. I'm pretty sure it isn't the O2. I'll try to get under there and Ohm the wires today. I just need to find the PCM wire schematics

[pajeff02]

I have schematics for our '02 if you want me to send you the info. I presume the '99 and '02 should be the same.

[clewis05]

I have schematics for our '02 if you want me to send you the info. I presume the '99 and '02 should be the same.

That would be awesome if u would man. Email is c_lewis_05@yahoo.com

[pajeff02]

Ok - bump this thread tonight if I don't get it out to you as a reminder.

[clewis05]

ok - bump this thread tonight if i don't get it out to you as a reminder.

bump