I have a 2006 Crossfire Limited with about 103000 miles. I runs and idles great, but when I increase the RPM's to above about 2700 rpm, the check engine light comes on with P0300, P0301 and P0306 - misfire codes. Here is what I've done:

• Engine compression test - lowest was 165 psi (only one) others were all around 170 to 172 psi.
• replaced Cam shaft and Crank sensors - with Bosch
• I didn't change the spark plugs, they look new
• checked coils - exchanged coils around to different cylinders, but still got the same codes
• checked for blocked cat's (first I disconnected them, and then even put it back together and tried just taking out the O2 sensors)
• checked for vacuum leaks and replaced old cracked hoses (I did not do a smoke test, but may if you think it is necessary)
• When I got it, it was missing the EGR valve, but I got one from our local pick-n-pull and installed it
• O2 sensors seem to be working.
• Fuel pressure is at 55 psi
• I had the fuel injectors cleaned and tested

Anything else??

Any suggestion would be greatly appreciated!!

 

Hi, sorry to hear about your problem. Do you get the misfire at 2700 rpm under load, or parked? Sounds like it could be the fuel injectors - when you say you cleaned and checked them - does that mean you removed them? Did you examine the o-rings around the injectors to see what shape they are in? You can carefully spray carburetor around the injectors to see if the engine reacts (maybe spraying water or a smoke test is safer).
Good luck
-Jerry

 

For me, it was anytime I'd go over 3000, I'd get misfire codes. If I had the pedal near the floor at the time, I also had O2 codes.

12 plugs and 12 wires fixed it all. That was with my second roadster, around 105,000 miles.

 

I found the problem .... It appears to be a clogged exhaust system, I'm betting the catalytic converter(s) is/are bad. Not sure why the first time I checked that didn't seem to be a problem. I removed the forward O2 sensors and revved to above 2700 RMP and no codes. I even drove it down the highway with no problems, other than it was a little noisy with the exhaust going out the O2 sensor holes ... lol.

 

Thanks for the update!