05gtgreen

I am starting to notice that when I start my car, it seems to be misfiring or something after it sits a while. If you go to leave right away, it seems to be missing bad for like 10 seconds then it will be fine afterwards. I really noticed it today when my dad left with my car, I could hear it really bad in the exhaust, but once he got to the end of the street it seemed to be fine. What could be causing this. I have been throwing a P0152 engine code for some time now, dealing with the oxygen sensor, but I was told that this shouldnt affect anything, but the car ran fine before i started getting this engine light. My mods are listed in the signature below.

shaners90lxhatch

If you are setting that code, youhave a shortto power on an 02circuitYourtune may have something to do with it.... the cold start fueling strategy may not be good enough to keep it from missing all the time. I wonder why you havent thrown a P0316 (misfire on first thousand revolutions)......I suppose the tune may have a different code threashold as well.......Try some different gas. Maybe the seasonal fuel for your area is not good enough. If it is abnormally cold for your area for this time of year, the volatility of the fuel may be too low and it just may be hard for the motor to turn on cold start. Could be carbon deposits too. Especially if the gas you typically use is too high octane or just downright crap.Otherwise you need to make some repair attempts or get the right equipment to figure out which cylinders are dropping out (if any) as well as see what everything else looks like as well......

05gtgreen

I have been running a 87 octane tune. got the tuner and CAI from brenspeed. Everything ran fine until I threw that code. Not sure if its a misfire or not, its almost like its flooding itself out, but it goes away right away. Maybe I should let the car warm up a little longer before driving. I called Brenspeed and talked to Dave, and he said that not to worry about it cause its to do with the O2 sensor and the headers. The car runs perfectly fine afterwards. Its just when it sits for a while, I will notice it right away.

Daniel60

owero01

Very inappropriate for this forum.

PROMETHEUS PRIME

?????????????????[sm=shutup.gif]