LSJ running rich

[jakemcd]

Hey everyone,

I have an 07 Cobalt SS with ZZP stage 1 kit (3.1 pulley), with ZZPs canned tune, and intake.

The car ran fine for the first couple months after installing the kit. Although it did have a fuel trim rich code.

After the first couple months it developed a problem that occurs only at WOT. it will buck and sputter and has no power at all.

I am a noob when it comes to tuning and I'm looking for the easiest way to lean out my fuel trims all across the board but especially at WOT.

I've attached the tune file and a log for reference.

Thanks,
Jacob McDearmid.

[Area47]

wideband?

[MarkTucker]

Yeah you will need a wideband and then you can log AFR Error in the scanner. Then you can copy AFR Error from the Histogram and paste multiply to the MAF Calibration for WOT tuning. And for dialing in the MAF for cruising and normal driving(not in PE), just dial in the fuel trims. You can scan LTFT+STFT vs MAF HZ in the Histrogram and copy and paste multiply in the MAF calibration table to dial in fuel trims.

[jakemcd]

I don't have a wideband installed. Is there any way to fix this problem without one?

[MarkTucker]

Yes you can. Just dial in your MAF Calibration until your fuel trims are closest to 0%. Then monitor your knock retard when you doing WOT pulls. But knowing your AFR for WOT pulls is very important. You can not tune off of the fuel trims at WOT if you didn't know this already. Your fuel trims disable when you enter PE.

[Sharkey]

imo, if the car ran fine for a couple months after putting the zzp tune in, then your problem is likely not the tune.