I have a post in the mach1 section but I bought a scanner and one of the codes it gave me is not in the manual. I got the codes p0300 (misfire) and the code p0316 and I do not know what that one is. Can anyone help.

 

i know p0300 is a multiple misfire code and it's usually accompanied by a code for a speciific cylinder, are you the other code wasn't p0306?

 

p0300 is random misfire, and p0316 is misfire on startup

 

Do the car feel like its missing under load?

 

when you are just cruising is when it misses. if you get on it the car runs great. idle you can hear the miss but not realy feel it. if you run about 55 in 4 or 5 gear the car will buck and jump. If you give more gas the miss goes away. any suggestions on where to start is greatly app.

 

my codes are p0420 catalyst system bank 1, p0430 same bank2 ,p0300 misfire,p0316, misfire start up,po442 evaporative emission leak small,

 

420 and 430???

Does the car have the factory H pipe??? You got bad cats dude. Unbolt the h-pipe at the collectors, leave the h on, but with like a 1 inch gap and see if it runs any better.

 

As for the evap code, check the filler neck + filler neck seal. Its either that or one of the EVAP lines..or a bad vapor management valve

 

+1 check your fuel cap too

i'm guessing he has an o/r mid pipe