Tune-up parts are they OEM parts? P0300 is normally caused by vacuum leaks and bad gas.

Might want to check the airfilter and fuel filter conditions to complete your tune-up.

loss of compression, and anything that causes an unusually lean fuel mixture (lean misfire), an EGR valve that is stuck open, dirty fuel injectors, low fuel pressure.

Answered by rasmataz
68 questions asked

Replaced all filters, wires plugs cap and rotor good pressure no vacume leaks. the dealer has it now and they ran injector service on it and gave me a 6 page instruction on reseting the computer. the light still comes on. is it possable that the internals of the intake leak. they say that the valves have varnish on them causing them to stick. but with 17k miles since the code came up I have a hard time beleving that.

Response from chevy169
2 questions asked

Could be valve problems-if they did a compression check

Answered by rasmataz
68 questions asked