P0171 Code After Belanger Full-Exhaust Install (w/high flow metallic substrate cats)

[Vpr898]

1996 GTS 9,500mi

I completed the installation of the full exhaust system from Belanger Headers today; long tube headers, high flow cats (metallic substrate), and cat back.

Ran the car up and down the street after the install a few times and on one of the runs, the P0171 (Lean Bank 1) code was generated.

To me, it's obviously something I did, but what?


- I don't believe it's on the intake side, as I would expect the other bank to read lean too (P0174 code, not generating). I also didn't mess with the intake side, vacuum lines, etc.

- The upstream O2 sensors had some seriously twisted cords and they got twisted further and back during the install, perhaps I ruined the leads on the bank 1 upstream sensor. I'm going to try swapping them to see if I generate the P0174 code instead of the P0171 code.

- I'm also considering an exhaust leak. The upstream sensors are located in the runners for cylinders 3 (driver's side) and 4 (passenger side), I'm thinking the only leak that could affect those sensors would be the header gaskets themselves, which were entirely intact when installed. The header bolts are all tight, and I don't hear any leaks up there, but it's being considered. Leaks downstream from the first set of O2 sensors couldn't be causing this, right? I also don't have reason to believe there are any leaks along the entirety of the system. The downstream sensors couldn't be generating this code, right?

- The brief instruction sheets from Belanger have a note that reads: "This product, in conjunction with your Viper's computer, requires at least 500 miles to recalibrate for air/fuel, timing and other critical settings to "dial in" properly. Running your Viper on a dynamometer (dyno) during this critical re-calibration time will result in poor "dyno" numbers and your Viper motor running hot." Does anyone know to what extent this "dialing-in" occurs and could this note be related to the issue I'm having?

I wrote down my thought process in the hopes of sparking any tips or suggestions from the community. I'm on my own here and this has been one of my few bigger projects.

Thanks very much

 

[Geronimo]

Re: P0171 Code After Belanger Full-Exhaust Install (w/high flow metallic substrate ca

I would just drive it and see if the check engine light goes out. If not you can get some spark non-foulers and drill out the center for the rear O2 sensor to fit. Use on rear only. That's what I did. I later went catless and light did not come on with that either. Or drive it the 500 miles and see what happens. ECM re-flash is an option to if emissions isn't a problem.

 

[Vpr898]

Re: P0171 Code After Belanger Full-Exhaust Install (w/high flow metallic substrate ca

Yeah I thought about grabbing some O2 isolators if I was going to be having issues with catalytic converter codes, but that's not what I'm seeing, this doesn't even seem to be a downstream issue. What were you seeing when you decided to isolate your downstream O2s?

 

[Geronimo]

Re: P0171 Code After Belanger Full-Exhaust Install (w/high flow metallic substrate ca

Yeah I thought about grabbing some O2 isolators if I was going to be having issues with catalytic converter codes, but that's not what I'm seeing, this doesn't even seem to be a downstream issue. What were you seeing when you decided to isolate your downstream O2s?

I kept getting a check engine light after header/ hi flow cat install. Don't know the code forI didn't have a scan tool but I installed spark plug non-foulers in the O2 downstream on both sides and fixed the problem. A few months later I dumped the cats and still no check engine light. Good to go. I imagine it was probably the same code thinking the rear O2 sensor is reading lean for introducing more air with big headers. Try the spark plug non-foulers first. They have to be drilled out for the O2 head to thread in. Can't remember what bit size, 1/2" inch maybe. Size up the head to a bit slightly larger.