P131, P151 codes Fuel pump?

**TransAmX2** · 06-10-2011, 12:52 PM

ok, so I've installed headers and ORY and had Frost mail tune my ECM and delete the rears, but I'm getting the front O2 codes when ever I get into it 3/4 throttle or more it seems.

I replaced my fuel filter and ran a can of fuel injector cleaner in it and that seemed to help, I cleaned my Mass Air flow and it didn't really seem to change anything. If I don't go past like 2/3 throttle the SES light doesn't come on and it runs smooth but almost every time I do get on it, it pops the code and then runs a little rough when I'm in the throttle (starts accelerating fine then stutters for 1/2 a sec then catches and accelerates hard and repeats, etc.).

I have been resetting the SES light whenever I work on it but sometimes it resets itself after a little normal driving. As far as I can tell the next step is to either get a fuel pressure gauge or a scanner to monitor the fuel while I'm driving. This sound right to all you guys?

BTW this fuel pump was a brand new GM pump installed about 3 years ago so it likely only has 15-20kmi on it.

Anyone have suggestions on pressure gauges/scanners?

**JayTA98** · 06-10-2011, 01:07 PM

Originally Posted by TransAmX2

ok, so I've installed headers and ORY and had Frost mail tune my ECM and delete the rears, but I'm getting the front O2 codes when ever I get into it 3/4 throttle or more it seems.

I replaced my fuel filter and ran a can of fuel injector cleaner in it and that seemed to help, I cleaned my ass Air flow and it didn't really seem to change anything. If I don't go past like 2/3 throttle the SES light doesn't come on and it runs smooth but almost every time I do get on it, it pops the code and then runs a little rough when I'm in the throttle (starts accelerating fine then stutters for 1/2 a sec then catches and accelerates hard and repeats, etc.).

I have been resetting the SES light whenever I work on it but sometimes it resets itself after a little normal driving. As far as I can tell the next step is to either get a fuel pressure gauge or a scanner to monitor the fuel while I'm driving. This sound right to all you guys?

BTW this fuel pump was a brand new GM pump installed about 3 years ago so it likely only has 15-20kmi on it.

Anyone have suggestions on pressure gauges/scanners?

Are you using the OEM O2 sensor that came with the car? Have you contacted Frost and explained him this issue? I have heard of some O2 sensors poping the SES light. I see that alot of members get the denso or Bosch brand for corvette because of the longer wiring.

I don't think is fuel pump related but it you can get a fuel gauge and check the pressure it has to be around 58-60 psi. Clean your Mass Air Flow sensor(not ass air flow lol) with MAF cleaner.

I will start by contacting Frost. He might be able to make some adjustment. He looks at the section often. I'm sure he will chime in.

**bpopham22** · 06-10-2011, 04:48 PM

Didnt pinch any wiring harnesses on the header install did you? Did u let the headers heat up and burn the coating off before installing the o2 sensors?

**TransAmX2** · 06-12-2011, 10:06 AM

I am using the OEM o2 sensors, and all 4 worked before the swap without codes. I kept the front sensors and swapped them onto the headers and put rear 2 in the garage.

I did clean my Mass Air Flow with MAF cleaner (not ass air flow

) .

I don't believe I pinched any wireing I zip tied all wiring away from the headers where they were loose at all, it doesn't really seem to me like a likely cause because like I said, if I don't go past 2/3 throttle there is no code thrown, I'd think any wiring issue would be a hard fault so to speak and always be active.

I did not burn off the header coating before installing the o2 sensors but again, I would think that any o2 sensor problems would always be present not just appear when I get into the throttle. I could be wrong tho. I can always swap out these 2 sensors for the other 2 I have.

thanks for the input so far

**Joseph_98** · 06-13-2011, 07:32 PM

this is my exact problem here.. did you get it fixed yet? and what did you do?

**TransAmX2** · 06-14-2011, 06:54 AM

Originally Posted by Joseph_98

this is my exact problem here.. did you get it fixed yet? and what did you do?

not yet, was waiting to see if Frost would chime in before I spend $200 or so on a fuel pressure gauge or programmer. I might swap in my other 2x O2 sensors just to totally eliminate the possibility of it being an O2 problem.

**Joseph_98** · 06-14-2011, 08:05 AM

auto zone let me rent a fuel pressure tester and i bought a cheap code reader there for like 50 bucks lol...hey man if you do figure this thing out please please please let me know lol!!!!

**Joseph_98** · 06-15-2011, 09:56 AM

anything change yet?

**TransAmX2** · 06-17-2011, 11:25 AM

Originally Posted by Joseph_98

anything change yet?

well.....it's all better...and I didn't do anything else to it

only thing I can figure is it was the fuel filter/injectors and after replacing the filter and running a tank of injector cleaner through it it just took a dozen or so cycles for the computer to adjust and it's been fine since.

I've done quite a few full throttle runs and gone on a 90 minute road trip which included some constant 80mph highway speeds and some stop and go traffic and it never missed a beat. It seems to be stronger, chirping the tires or spinning them more often with less gas pedal effort. Wish I could provide more information on exactly what fixed it, but i'd rather have it fixed and not be 100% sure why than still throwing codes and leaving me clueless.

damn gremlins...

**JayTA98** · 06-17-2011, 06:41 PM

maybe you had bad gas?

**TransAmX2** · 06-20-2011, 05:50 AM

Originally Posted by JayTA98

maybe you had bad gas?

I thaught about that also but this was all continious through 3 tanks of gas

**Ls_won** · 06-22-2011, 06:36 PM

mine did the same thing til i cleaned the maf, these cars i know are wierd about gas. i run 91 to 94 all the time, and can for sure tell a difference between the octane ratings.