engine misfire

[mrazekt2002]

When I was going to pass someone the engine went into passing gear and wne up to around 5000 rpms, then after a second the car died. I was able to start the car again but it ran terrible. when I got it home I checked the error code that showed up. The code was P0300 (random/multiple cylinder misfire detected).

My dad thought it might be a spark plug failure i think it might be an ignition coil. PLEASE HELP.

[BNaylor]

Check basic stuff: ignition and fuel. Spark plug, plug wires. Fuel pressure and fuel injectors.

Since you have a 2001 model GTP have the CAT convertor tested because GM delivered 2001 - 2002 models with possible defective CAT convertors.

[mrazekt2002]

I removed all the spark plugs and the front three had there gap reduced. The middle and right one (facing the engine) were completely smashed against the electrode. The left one had a gap of .032. The back three were gaped around .060. What is the correct gap, because I cant find it in the manual? There is also a mild knocking sound that comes and goes. It mostly shows up when the engine is reving down (in neutral). I haven't drove it yet so I dont know if there is any lose of power, but the exhaust used to sound fairly smooth now it kind of bounces occationally.

[BNaylor]

Originally Posted by mrazekt2002

I removed all the spark plugs and the front three had there gap reduced. The middle and right one (facing the engine) were completely smashed against the electrode. The left one had a gap of .032. The back three were gaped around .060. What is the correct gap, because I cant find it in the manual? There is also a mild knocking sound that comes and goes. It mostly shows up when the engine is reving down (in neutral). I haven't drove it yet so I dont know if there is any lose of power, but the exhaust used to sound fairly smooth now it kind of bounces occationally.

The stock AC Delco Platinums or Iridiums should have a .060 gap.

[mrazekt2002]

thanks