Ok So recently I had installed a UUC System U Single Canister cat-back on my '95 325is. After this upgrade I decided to order a Conforti chip. It arrived days later so I disconnected the battery and I immediately installed it. I hooked up the battery again and went to start the car. The car would turn over but wouldn't start. After many attempts I finally decided to throw my stock chip back in. I figured maybe they had made a mistake and sent me the wrong chip. So once I had everything back together including my stock chip, I started the car. The car immediately started but during idle about every 25-30 seconds it would sputter and the rpms would drop and would sometimes rebound but other times it would stall. I let it run for about 15 minutes and the whole time it would keep sputtering. I took it for a 5 minute ride and parked it once again and it still kept doing the same thing. I figured since I disconnected my battery and played with the computer, that maybe the Idle Air Control valve was faulting and the computer was just trying to re-learn itself but I thought after at least 20 minutes it should have worked itself out. Plus of course, by disconnecting the battery (not thinking ahead), my damn radio is locked out now. So now I have some problems on my hand. Sorry for the long story but I'm trying to provide everyone with the exact details in case some one has gone through this before, or knows any information that could help me out. So really I'm wondering a few things: Do you think that the idle problem is just a simple computer re-learning process or a major problem that stemmed from something else (although before the attempted computer upgrade my car ran excellent)? Also I wasn't thinking ahead when I disconnected the battery, (and it obviously resulted in the radio lock out) and of course I don't have the code, so I'm not sure of the process I need to follow in order to get the code or to simply solve this pain in the ass problem. After all that hopefully someone could help me out or maybe have any info that would be useful. I just hope the running problem isn't anything major, 'cause I would hate to find out that in an attempt to upgrade my car that I actually ended up screwing it up majorly. Thanks for anything you guys can come up with. I appreciate your time.