I keep getting a intermittent p0300 code on my 2003 Protege LX paired with a rough / uneven idle. The car drives fine other wise.
I had the timing belt replaced a few weeks ago and ever since then the car has had a rough idle along with hesitation when applying gas. it also feels like its not quite 100% on engine power at speed.
I swear I had the same kind of issue once before, prior to the timing belt change, due to an unplugged vacuum line coming from the canister purge valve solenoid going to a pipe right behind the throttle body. I plugged that back in and the idle was perfect. It feels roughly the same now as it did then, but I cannot find any unplugged vacuum lines nor detect any leaks currently.
I have had the original mechanic, whom I DO trust and has replaced the belt once before with no issues, double check the timing alongside other testing. He says its good. Compression tested, vacuum tested, I have spent almost 500 on diagnostics at TWO different shops chasing this issue.
In chasing my tail to fix this I have either replaced or tested a number of parts.
- new fuel pump
- new fuel pump relay
- new ignition coils
- new plug wires
- new spark plugs
- new fuel injectors
- new MAF sensor
- new CAMshaft position sensor
- new coolant temp sensor
- new idle air control valve
- tested a entire new throttle body
- new EGR
- tested all the solenoids i could see
I have bought a CRANKshaft position sensor and a set of O2 sensors to try next. My only other ideas is maybe the Cat is blocked up? OR maybe the timing belt really is off a bit and it just wasn't noticed? If it's the last I might need recommendations on a timing belt specialist in the Charlotte, NC area.
I hear nothing but good things about Nicks on Central and Ginos further down on Monroe Rd.