mikolsautoservice wrote:Has anyone had similar problems on a 2000 Impala? Code P0304 is coming up and cas is missing. New plugs, wires, compession is about 135psi on that cylinder. Power to fuel injector good. Getting gas to cylinder. 3.8l Could the intake gasket be leaking?
Hopefully you have this resolved, but if not, & for future reference, here are some thoughts:
What is compression on the other cylinders? Valve sealing or sticking can give intermittent misfires which can escape
detection by a routine compression test. An aggressive fuel injector / carbon cleaning session may help if it hasn't
gone too far. If it has, valve job.
New parts does not mean good parts. Use only top quality parts and retest.
Vacuum leak possible. Observe fuel trims at idle, then under various driving conditions. If adding fuel at idle,
but ok at other times, vacuum leak very possible. Double check on dead cold engine with smoke or propane.
Look at freeze frame or failure records for this code. This will help tell you when & how code set.
If you fixed it, please post what you did so everyone can learn from it.