P0306, P0420, and P0153

[Mussolini1996]

2002 - V8 - 70,000 miles

So my check engine light came on and I just figured it was time to replace another coil, 3rd one since I bought the car. So I hooked her up to a scanner, to figure out which cylinder was misifiring, and got the 3 above codes. P0306 Cylinder Misfire on Cylinder 6 was the first code, so I replaced that coil. Still having a stuttering problem under light acceleration once it's warmed up. So then I replaced the 02 Sensor on bank 2 sensor 1. Still not running right. I took out all the spark plugs, replaced 2 that might've been going out (including cylinder #6), and still to no avail. I'm thinking I may have a clogged catalytic converter, but am not for sure. I haven't scanned the car again to see what codes it's come up with now. The check engine light hasn't returned, but I have barely driven it.

Has anyone else had a similar problem, if so, how did you resolve the problem? I really hate taking my car into a mechanic, but it looks like I might have to do that in this case.

 

[bearsfan39]

replace all the cops and spark plugs first

 

[SlickLS]

Check the connection on your fuel injectors with the car running to see if it will clear up. I had a misfire problem and replaced the coil and still had the problem. I pressed on one of the fuel injector connection and it instantly cleared up and my car was fine. Good luck and I hope you problem was as easy as mine.

 

[Mussolini1996]

Still having the same problem, haven't gotten it fixed, because I don't drive the car much, but now I may be looking to sell it. I talked to a muffler shop, and the guy there said he doubted that it was a cat problem. He thought it was a possible fuel injection problem, that there was too much fuel coming in. Any other ideas???