Po 300 Code On 2001 Silverado 6.0

[franksmonte]

Can not get rid of code, missfire on 1,5,6,8 . Tried plugs, wires, fuel filter, fuel rails with injectors, coil packs, compression and cam check. cleared code but comes back the same. I also tried a d-carb prosess. Any Ideas?

[Indy]

Can you feel the truck misfiring? Do you get a flashing CEL which indicates a serious misfire? Could be a computer (PCM) problem.

[franksmonte]

Can you feel the truck misfiring? Do you get a flashing CEL which indicates a serious misfire? Could be a computer (PCM) problem.

[franksmonte]

Can you feel the truck misfiring? Do you get a flashing CEL which indicates a serious misfire? Could be a computer (PCM) problem.

 

I`m not sure, the truck seems to run OK, The CEL starts flashing when I get to highway speed,(2600 to 3000 rpm). Then it stops. When using a snap-on scanner it says its missing but I don`t feel it.

[franksmonte]

Where is PCM on this truck, and whats the diff between a ECM and PCM ?

[franksmonte]

NO other Ideas on this?

[J45p3r]

Where is PCM on this truck, and whats the diff between a ECM and PCM ?

PCM and ECM are the same thing. It is located under a black plastic cover next to the battery (not to be confused with the underhood fuse box).

 

PCM: Powertrain Control Module

ECM: Engine Control Module

 

On these trucks you'll find both names used.

[minibike132]

I wold do a crank position variation relearn before you get too crazy replacing the pcm. If somewhere along the line the pcm lost the crank variation it would cause false p0300.

[mi.bowtie]

Are your 02 sensors and y-pipe original equipment. Try scanning the 02 sensors to make sure they are in the right parameters.

I'll bet they are bad, or Your Converters or both are bad.

[franksmonte]

Crank position relearn, can I do that with a snap-on scanner? Or go to dealer?

Also o2 sensors, y-pipe, and cats all original with 100,000 miles. How do I check cat convertors.

Thanks for help!

[minibike132]

can I do that with a snap-on scanner?

 

I don't know. Just a quick Google search says yes but I couldn't tell you how to do it. Generally build the vehicle and go to special functions and if supported there are usually instructions under a crank relearn item in the menu.