I was wondering how many people that have experienced any of the misfire codes are running a catless exhaust system.

 

I've got the P0300 both with and without a catalyst.

 

I got it more after the Cat. taken off.

I went and got the dealer flash and it sorta disspeared. I had the p040 "lack of cat" codes but looks like the dealer flash took care of that too.

 

The dealer would not even look at my car since there was no cat on it. I wanted to get the dealer flash for the misfire code and they said it was because my cat was gone. A lack of required backpressure night be causing my problem is what he thinks, but they can not look at it under warranty since I have modified the exhaust. No boost controller, just K+N drop-in and a 3" downpipe back with no cat. Not too happy right now.

 

That is B.S. I can't believe the dealer told you that.


On topic: Seen it both with and without the cat. Can't say which has had more instances. Mines more random than anything else.

 

without cat. and still having plm with p0300. i did went to the dealership and have them to flash my ecu and after that it went out.. but after abt 100 miles later it came back on and still p0300.. what should i do? anyone out there any idea?? Thanks!!

 

any 04s having this problem? or just the 03s?

 

I think it's both. Less instance on 04.

I think a lot of people are getting that again after 100 miles after the flash. I have more than 2000 miles since I got and no CEL light so far. I just hope it'll stay that way.

 

The P0300 = Random Misfire.


I have it, the cat code is different.

 

cat code is P0400

 

comes back approx 300 miles after dealer re-flash.