[kriot3]

Hello everyone.

For the last week whenever i make a cold start on my 2000 cat it idles rough for about 5 minutes. During this time sometimes it may shut off and I have to restart it. Reving it doesnt even work cause it just idles even lower and may backfire. Almost doesnt even take the gas pedal at all. Eventually as it gets a bit warmer it idles better although there is a slight vibration. It drives ok when warm but you can still feel the misfire.

I pulled the codes and it gave me 300 301 and 303, so I changed the 1-3-5 coil pack and its still doing the same thing. Any ideas as to what could be causing this?? Thanks

 

[CateraMV6]

Try reseting the Idle Control System by leaving the ignition on for 6-7min with the engine off... and that will force the throttle body to relearn its preset positions and should smooth out the idle.

Mine does that every time I disconnect the battery, and I have to redo it every time...

Should run smoother after that...

 

[kriot3]

Thanks CateraMV6. I tried it but had no luck. Left the key in the on position for almost 10 minutes with the car off but it didn't help. Anything else I can try or other thoughts?

 

[jwaithaka]

Hallo Kriot3, I have a 97 deville and seem to have the same rough idling problem when cold. service engine light comes on for a while and then goes off by itself. i have done tuneups twice, changed the coil pack but still have this problem. anymore suggestions?

 

[kriot3]

Problem is my MAF. I disconnected it and the rough idle stopped. jwaithaka I don't know much about the Deville but it wouldnt hurt to check it out. Just have to find the replacement part now although they can be pricey. Thanks guys

 

[CateraMV6]

Try Rockauto.com or ebay... those are your best bets...