Ok, so heres the problem. A few months ago, my car was running awesome, except that I lost a lot of low end torque, and I wasn't able to spin the tires. Then, about 2 weeks ago, I noticed that my car wasn't downshifting properly, sometimes not at all. Before when I floored it, it'd shift at 30, then 60, then idk, but now it was shifting at 35-40, then 65+. Now it's getting bad. It's running EXTREMELY rich! I just put new exhaust on about a month ago, and now when I stick my finger in teh exhaust pipe, its as black as night. When I start it up, it goes to 1000 rpms, then drops to 250rpms, then skyrockets to 2000rpms, then eventually comes back down. When I drive it, it has no acceleration power anymore, and if I stop at a stop light, it'll drop the rpms to about 250, then the engine will stall. Sometimes when i have it in drive,and my foot off the gas, Itll go from 500-1000, then back to 500rpms. Whats wrong with my car?

 

Well, your problem sounds like you are running rich.

Check the basics - MAP working? TPS working? What's your fuel pressure? At idle? Key on, engine off? O2 sensor dead?

 

IAC maybe

 

IAC... I had the same problem about a monthback. Get some carb cleaner and a toothbrush and clean it if not replace it. Sometimes when they get lots of build up they make the car run bad, you might also consider cleaning the throttle body.

 

I had a very very similar problem after I put in the amp in my car. The idle strategy in the computer got erased and the car would stall at lights, idle weird then just die and all kinds of annoying crap. I had to unplug the battery for like 5mins, plug it back in then go drive around for 20mins and it was fine.

 

yeah, funny thing is that this all happened AFTER I unplugged the battery, weird eh?

 

There is an idle learn procedure that will help with the stalling, surging and other lousy results after a battery disconenct:

https://www.thirdgen.org/techbb2/sho...idle+AND+learn

However, your problem sounds like there is more wrong. If it is running rich check the fuel pressure regulator by pulling the vacuum line off and checking it for fuel. Do a key on (no start) and see if any fuel comes out of the line. If so, then FP regulator is bad.

Could also be a bad injector (leaking), or the ECM went south.

RBob.