FireSS

Just installed a stage 1 procharger and a speed density tune from PCMofnc on an 02 c5 base A4. They tuned it before through email. I have the 2 bar map sensor but it won't start and there closed till Monday. If I install the Maf tune it will run decent but then surge and seems like it goes rich, but Im guessing that's normal because of the 2 bar map sensor. I also get a code for too much air flow which seems normal to me with the blower. Anyone have any info on where I should start. It's basically a stock motor and manifolds with the blower, 60lbs injectors , boost a pump and ported throttle body. Thanks

tblu92

All kinda depends on how much boost you are making--- The STOCK MAF table on a 2002 C5 goes up to 12000 HZ this relates to the airflow of approx 500 crank HP---ty piclly doable with about 6 lbs of boost and still being able to use the STOCK open/closed loop tune and your MAF If you have more than 6 lbs of boost and with data logging your MAF the MAF table exceeds 12000 HZ then that's the only time I would use something other the the stock OL/CL tune set up---And speed density is not your only option---Many people experience better driveability with what they call a "semi open loop tune"
You need to find out exactly where you are at--by having a tuner do some data logging 1st using the MAF OL/CL tune and see if you exceed 12000 HZ--
Truing to diagnose your check engine lite is impossible without knowing the exact DTC number---

FireSS

Thanks. I figured it out. It ended up being a bad brand new 2 bar map sensor. I have a new one coming from dealer.