scottjt13

09 ss/tc full treadstone bolt ons, zzp catless downpipe, zzp canned tune ecu, gm stage 1 map sensors.
I just installed the zzp ecu and 3 bar map sensors with plug and play harnesses. These parts cured my existing problem but a new one came up. I now have a very rough idle until warm. So rough that sometimes it will die if I'm not on the gas. Stft are at 29.7.
I did a little experiment and unplugged the maf sensor this morning and it started and idled with ease. My maf sensor is new and I even swapped it out with my old maf with same results. I dug up a thread from 8 years ago talking about how the maf sensor could be grounding itself on the intake pipe skewing everything. Wondering if this could possibly be my problem.
Also did a boost leak test and everything was good.

Slowbalt2000

iTrader: (1)

Its likely a leak on the intake or the maf scale is just that far off. Did you tell them what intake you had?

scottjt13

I said I had an injen intake because I had an injen filter because it's all I had at the time and they did not have a treadstone on their list. I will be getting a new tune come spring I am not driving the car this winter I just got these parts to try and fix another problem I had before I parked it. I just want to get all my problems taken care of before taking it in for a dyno tune

Slowbalt2000

iTrader: (1)

Well thats your issue then, they tune for a specific intake because they all have different maf placements.

scottjt13

Well im glad to hear that it's a tune issue and can be corrected when I start driving it again. Just glad these parts fixed my problems I was having before. I disconnected the evap purge solenoid harness to force ltft to stay at 0. Car still had rough start idle but it didn't show the p0101 code anymore and car was able to boost and it drives so well now best it has since I bought it in April. Thank you for your help

scottjt13

Also with evap connected and driving with no boost with p0101 pending always never throws a cel car drives nice just with no boost and after about 10 minutes of driving highway the fuel trims are both close to 0 within +2. Afr jumps up and down a bit not near as bad as before but between 14.3 and 15.8 and 14.7 commanded.

umrdyldo

iTrader: (1)

So your Long Term Fuel Trim is around 0? P0101 is often times a boost leak somewhere.

scottjt13

Long term fuel trims go up to around 15 and slowly start to come down to 0 within the stft. No boost leak checked a few times. I'm led to believe it's the canned tune because I never had the p0101 code before installing new ecu