sonic

thanks 1move! your right, it definitly wont be a sensor..worst case with them is that they would put the car in to safe mode. So no sensor.

So i went and got a new coil pack today...tested them....ding ding ding..we have a winner!!!

4th cylinder misfire based on the coil pack gone.

now the question is how do i get rid of the stupid check engine light. car runs great now!!

frob

Hey what do i know, i'm only speaking from recent personal experience!

Seriously, the O2 sensor can fail gradually leading to grossly erroneous air-fuel ratio. Same goes for the MAF. i actually had both happen to me on seperate occasions in the last couple of months. lots of stuttering, misfires. no problem with coils, and a new sensor fixed the problem each time.

Anyway Sonic I'm glad it turned out to be a simple coil pack. To clear the CEL you need to connect with a vac-com reader and erase the codes. A local mechanic will probably do that for you for free. Some CEL codes reset themselves after a certain time of normal running, but I don't know if that's one on them.

1move

iTrader: (1)

I can see the MAF doing that but the sensor??? It is just a signal it would only put you into limp mode if it was harmful and the engine light would be on constantly as this was not his issue....... Well glad you solved it, and you can clear the engine light with a cheapie ebay cable...... Good luck buddy

frob

The #1 O2 sensor is actually the primary input the ECU uses to manage and fine-tune the A/F ratio. The MAF input basically allows the CPU to work out a rough estimate of A/F, but if the two disagree, the 02 sensor, being more accurate, takes precedence. #2 O2 sensor is used mainly to monitor Cat converter efficiency, and doesn't enter into the A/F calculation. The ECU monitors the O2 sensor's health by looking at their heater resistance (heater burnout is the most common way they fail). But if the #1 O2 sensor starts giving an erroneous signal due to fouling etc, but the heater is ok, the ECU will believe it and try to compensate by adding massive correction factors into the A/F map - and actually throwing the A/F rato way off. A sign this is actually happening is also getting 2 other DTC's at the same time: AF correction high limit reached, and low limit reached too.

sonic

Ok so to get rid of the CEL light you just have to ask the car nicely. In the middle of driving i asked the car to "please get rid of this stupid light!!" and then it disapeared. LOL talk about being intune with your car. lol

Chaos

hmm maybe i should try that method with my car hopefully if i ask nice enough my ko3s will turn into a gt28rs for a while