1998 BMW M3

Automatic

WBSBK0338WEC39179

Please read this so you'll know more about this car. This m3 is aftermarket turbocharged. The turbo system is from Cartech. I have a receipt for $10,683 for the turbo system, the 3" stainless exhaust, the 1995 intake manifold, (better flow) intercooler, piping, etc. and a few other miscellaneous relevant parts (no labor). It was turboed in 2003. It made 350 hp and about 360 torque after the turbo. All that was installed by the owner prior to me. It's a well-engineered system. The wastegate is hard-piped in, the tubing is very solid, the turbo sits on the passenger side and out of sight, etc. However, now the car runs well only if it's not accelerated heavily. Under normal acceleration it runs fine. Around town, on the freeway, etc. But when I try to accelerate too hard and too quick the fuel mixture becomes too rich. I took it into a mechanic and wouldn't you know it the car wouldn't stumble for him. But for me it does. A "check engine" light comes on if I push the car too accelerate too hard. I have a code reader, it's always the same thing "cylinder misfire" but not the same cylinder. I erase the code and then just drive normal again. It could be something simple, like a sensor (coolant, oxygen), or something more complicated like the tune itself. I know it's not mechanical, the cars runs excellent if it's not put into hard boost. We don't, in my smaller town, have anyone who knows how to deal with this kind of aftermarket stuff. I was thinking about just putting it back to stock: I HAVE ALL THE STOCK PARTS, WHICH COME WITH THE CAR (except the exhaust pipe, but I do have the stock exhaust manifolds). I even have another stock ecu unit (the one in the car has been tuned for the turbo). Anyway, I decided to just sell the car as is. Someone may be able to figure out the too rich fuel mixture problem and keep the car turbocharged, or they can just take it back to stock and sell the turbo and kit. I'm getting too old (60) to do much tinkering anymore. One more "problem", the back plastic window is cracked. I was going to put a new one in ($129 at emiata and a couple of hours of work, see their website. The new back window just zips in and yes, mine has a zipper). I can put one in or let the new owner do that. So, that's all the bad news. The good news. I'm planning on selling this for less than the turbo system originally cost and quite a bit less than the kelley blue book price. The car is very nice. Two door dings and a little mark on the front spoiler. The interior is clean and very nice. The rest of the convertible top is nice. The sound system is an Alpine cde-103bt. The blue tooth works great. The car is tight, sounds great, looks nice. Please ask any questions you might have. Thanks for looking.