Thanks. Hoping I can get some input on this. I have a appointment with a Bavarian motorsports shop to check it out next week. I am stumped and I don't want to just throw money at it without knowing the issue
It does have the pops from the exhaust but it doesn't explain the P0420 and P0301 misfire code unless the tune is not done right.
I found that the tensioner pulley assembly is loose and vibrating a lot at idle. The spring and shock are shot and the pulley jumps a lot. Do you think it's possible that the supercharger is slipping and that's causing the misfire issue?
15% alta, alta intake stainless exhaust and an unknown tune. The guy that I got it from said the only code that ever popped up for him was the catalyst inefficiency code p0420. But he never got a misfire code. He said he changed bank one sensor, one O2 sensor which is the lambda sensor. The voltage in readings for the O2 sensors seem okay. The short-term fuel trim is fine but occasionally when I'm accelerating the short-term fuel trim will go as high as 25 to 29+. But then I let off of the accelerator and accelerate again and the short-term fuel trims stay at zero. Adam Cole at idle short-term fuel trim say plus or minus 5. At idle long-term fuel trims stay around -16 and under boost they are around negative. 7 which makes me think it's running a little bit rich. Probably has to do with the tune. Not sure if running. Rich could cause an occasional misfire. Usually it's running lean that causes that The idle is not perfectly smooth, but that could also be because of the tune. I have an appointment with a performance shop to have them check over the air fuel and everything else. What's weird to me. Is that it has a traction control light pop on every time I get the misfire code.
The car pulls hard under boost without a problem but it does have a little hesitation from a stop for starting from slow speed and then you feel the supercharger kick in and it takes off
I have the map sensor on order. Will be here tomorrow, I've got a new fuel pump and fuel filter on order to replace since it has 150,000 mi and I don't know if it was ever replaced. I'm going to go ahead and do that just to be on the safe side. And I picked up a 6PK 1364 belt because I'm running a 15% pulley and I have the ATI harmonic balancer that's 2% larger. I already have the tensioner assembly so I'm going to try to knock out everything tomorrow.
I already have the tensioner tool