Hello All, I just purchased a ZZP stage 2 kit with the #42 injectors, 2.9" pulley, GM belt and sent out the PCM to be flashed. After 2 days of driving my check engine light came on. PO171, system lean.

Here are my Performance Mods I have had for the past 2 years without any issues and still covered under the GM warranty.

- ZZP stage 3 Heat Exchanger
- Hahn 3" cat back
- Injen intake

I mentioned the Intake as many know the lean code can be tripped by those being on the car. I have had it for two years with no issues.

I know most of the causes but there are to many to test for in short time. I am looking for someone who had the same issue or same experience with ZZP and can point me in the right direction.

I am not having idle issues but i do get the slight bucking in second gear that has been noted as normal with our electric throttle control system.

 

It's probably not causing any problems, but you have a canned tune. A custom tune would be your best bet.

 

Someone else mentioned that's since the tune reset the PCM the lean could be from the CAI as it needs to relearn again like it did 2 years ago when I first installed it.