Misfire 2004 Century

[Dave Red Dziedzic]

My Buick is running rough. Parked it in the summer. At that time code DTC 0128 and DTC 0P300. The car sat until a few days ago. Replaced the spark plugs. No change. Still running rough. Yesterday code DTC 0128 and DTC 0P300

Any suggestions on how to fix the random misfire?

Help!

Dave

 

[ryenie]

Code P0128 means engine didn't reach normal operating temp, could be stuck open thermostat or bad coolant temp sensor, or fans running constantly. P0300 is a random misfire, it can be anything from bad gas, plugs, wires, coil, ignition control module, bad crank sensor, bad fuel injector, clogged fuel filter, weak fuel pump, bad fuel pressure regulator, clogged air filter, map sensor. A bad sensor should throw a separate code so i would start with wires, fuel filter, air filter and run some seafoam through it

 

[ryenie]

Be advised, if you pour seafoam into the vacuum line at the air duct, it will smoke a lot, and I mean enough to get you pulled over, and enough to smoke out your front yard. I say this because it tells you that you can put it anywhere into your car and it will clean it, and through the air induction is one of them, but I don't think it warns you other than to do it outside