how to fix the code p0300.. on 2005 Chevrolet Equinox

i have a miss in my equinox when its idleing and when u first take off and when u get about 30mph it starts running ok.. i changed the spark plugs,and the coil pack and it still missing.. what would the problem be i checked for vacum leaks and there was none... can u help..

by in Bay Minette, AL on September 12, 2012
4 answers
ANSWER by on September 12, 2012
Another possibility is lean running condition caused by lowered fuel pressure. Check fuel injectors to make sure they are not excessively dirty or plugging up. Could also be some water in the fuel tank.
ANSWER by on September 12, 2012
ALSO, HAVE A COMPRESSION TEST PERFORMED TO CHECK FOR VALVE PROBLEM. SCANNER WILL SHOW CYL. MISFIRE. AS THIS CODE INDICATES RANDOM MISFIRE,SCANNER WILL SHOW HISTORY OF MISFIRES ON EACH CYL. THAT IS A PROFESSIONAL SCANNER, NOT JUST A CODE READER!
ANSWER by on September 13, 2012
this could be fuel issues,electrical or even pcm issues seek diag and est
ANSWER by on October 17, 2012
Had a similar problem. Took it to a mechanic and they changed spark plugs , but I was still getting the code and engine light would not go off. Finally took it to the dealer and they found that a small woodland creature (a mouse) had somehow gotten under my hood and was living in one of the compartments, had chewed on the fuel injecter, and left evidence of his existence on the fuel harness. Make sure your mechanic really looks good under the hood and not just a perfunctory peek.