Ok here's the issue i have a 02 mini cooper with 185k miles recently changed the plugs, wires, ignition coil, fresh full synthetic 5w30 oil and a new air filter all as of the past 4 days. But still getting a misfire on cylinder 3 it only misfires when i'm at idle at a stop light or just sitting there never feel it misfire when i'm driving the misfire goes away after about a mile when it starts to at stop lights.

Any ideas what i might need to do to fix this

 

And if i sit at a stop light and keep the RPM's above 1200 it wont misfire only when it sits at 800-900 RPM's ant stop lights or in my driveway

 

well i was going to say its corrosion on cylinder three lead of the coil pack but you have a new one..... might be worth taking it out cleaning the lead, and applying dielectric grease. its a known problem, lots of moister collects back there. do you have any lean code? or maybe even injector signal error code?

 

yea thats why i replaced the ignition coil there was alot of corrosion and a flat spot on one of the leads so i bought a new one and i did put dielectric grease on it. there is another code i found its P2097 Post Catalyst Fuel Trim System To Rich Bank 1, and a manufacture aux emissions code

 

Just another thing you might want to do is a compression test across all you cylinders. See what you get. If cylinder number 3 is really low you will experience a misfire at lower rpms. But if all are good then you can rule that out and look to more in the electrical part of the ignition. With what you have replaced thus far though I would do a compression test. That's going to tell you a lot at this point. Good luck!

 

thanks for the tip ill get it into the shop soon to get a test done on it don't have the tools at home to do that

 

At most parts stores you can rent or borrow a compression tester.. Theres a NAPA store here by me and they just let me use it.. But just a thought for you. good luck!

 

Sounds off but you may want to pull the valve cover and replace the four spark plug tibe seals, at about 100k 3/4 tubes were FILLED with oil and I had a similar problem. Also make sure the plugs are factory spec tight

 

Ill look into that. Got a new issue that started this morning on the way to work. A coolant leak developed on the passanger front looks like I get the pleasure of taking apart the front end of my mini to replace a water pump and going to do the radiator while im at it and probably the hoses yay for me lol