2002 GMC Sonoma GMC Sonoma Code p0301

[quote:01157448cc="sncdoc"]Engine Performance problem
2002 GMC Sonoma 4 cyl Two Wheel Drive Automatic 23000 miles

About one every 4 to 5 months I get the code P0130, #1 cylinder misfire. It almost always sets when the truck is idling. The code clears after about 50 miles and then doesn't return for another 4-5 months. I've replaced the #1 spark plug with no change.

Also I read in the Shop Manual that this code is sometimes thrown for the automatic when it is traveling on a bumpy road and the crank shaft and cam shaft gets off. I do have a long bumpy driveway, but the code doesn't usually come as I'm driving down the drive. There is a slight misfire sound when it is idling.

Any clues as to where to look?

Doug Simmons[/quote:01157448cc]

Hi Doug,

Well either you type the code i wrong or you looked up the wrong code not sure which but here is the Code Def for what you have listed...

P0130 Oxygen Sensor Circuit Malfunction (Bank 1 Sensor 1)

.

The code should be P0301, #1 cylinder misfire.

Sorry for the confusion.

[quote:76c1ba9a2d="sncdoc"]Engine Performance problem
2002 GMC Sonoma 4 cyl Two Wheel Drive Automatic 23000 miles

About one every 4 to 5 months I get the code P0301, #1 cylinder misfire. It almost always sets when the truck is idling. The code clears after about 50 miles and then doesn't return for another 4-5 months. I've replaced the #1 spark plug with no change.

Also I read in the Shop Manual that this code is sometimes thrown for the automatic when it is traveling on a bumpy road and the crank shaft and cam shaft gets off. I do have a long bumpy driveway, but the code doesn't usually come as I'm driving down the drive. There is a slight misfire sound when it is idling.

Any clues as to where to look?

Doug Simmons[/quote:76c1ba9a2d]

Hey Doug,

Ok, have you tried changing the #1 plug wire with another plug to see if the code moves from the #1 cylinder?

Check fuel pressure and fuel regulator.
Check for Vacuum Leaks.
check compression
check coil.

.

check the crank position sensor.
notorious failing part on these trucks that causes the missfiring codes.

does the plug have any white soot deposites? this would indicate a lean cylinder possibly caused by a dirty fuel injector.
(from personal experience)

I hadn't thought about the crank sensor. I'll definitely check that first.

The spark plug I took out looked normal, at least from my experience with normally functioning plugs. No soot, and just a slightly gray coating.

I'll try the crank sensor next since that is one of the easier things to check.