Running rich, Loss of power

[Pozobyt]

my 99 stock 420a eclipse has been running rich and missing for awhile now and I can't figure it out. every time I get the codes read, it just says Rich, misfire on bank 1. I've tried gutting my Cat, didn't help. I have some new injectors to throw in there and see if that fixes it.

along with the rich condition, it's sputters when accelerating sometimes, and it sometimes stalls in reverse, and it has barely any low end power at all. it's hard to pull onto the interstate or anything because it has lost so much.

What can I try? and what would cause all of this?

thanks

 

[Mizzat508]

I know my car is a gst, but I think the problems have similar causes.

Sputtering - Whenever I'd mash the gas, regardless of speed or gear, it would spit and sputter untill about 4500rpms then it would feel some power. However, it was still slower then it should be. I replaced my spark plugs with bosch platniums (all autozone had and I didnt feel it was necessary to run NGK's a step colder yet) and bosch wires. No more sputtering, smooth accel.

Running rich - I've had p0170 on the CEL forever, and havent found a clear answer on what it could be. Some say o2, some say a harness issue, well I replaced the o2 with a Bosch O.E. replacement, not the universal one (Its a Denso sensor in a bosch box, if you dont believe me I will send you a picture of the 02). Ever since I've gotten noticable better mpg (less filling up, though I havent done it out yet), and its felt alot stronger through the whole rpm range.

 

[Pozobyt]

I actually took the msd ignition coil off and put a stock one on and it helped the sputtering.

I'll try changing my 02 sensors and see if that helps.

thanks!

 

[Fotowntalon]

Don't put platinum plugs on your car, at least if you are 420a, not sure about the 4g63, they will make your car run funny because they are to cold of a plug.