I have a 2005 Chevy Silverado 2500Hd 2wd crew cab. 6.0 litre I have had the motor replaced. Ever since the motor was replaced i get a check engine light warning with erroe code 300 at 2300+ RPMs and 68 MPH. They have checked the coils, injectors. Plugs are OE Iridiums with new wires. They have checked compression, fuel pressure, and for leaks and or cracks in the manifold. Any ideas??? Could this be a computer thing. I never got an error or a engine light before with the old motor

 

Plugs are OE? Is that original equipment?If so, how many miles do they have, also is this a direct engine swap?

 

Plugs are new. New replacement plugs. Used exactly what the manufacture calls for. This was a crate motor from Jasper engines.

 

You only have this at 2300 rpm? Can you feel it missing? Is idle rpm ok?

 

Yes it only seems to happen at 2300 rpms or higher. I cant feel any miss firing at all. Idle rpm was checked and all is good. All sensors have been replaced. The coils have been checked, plug wires and plugs all replaced, injectors checked, and checked for cracks in head. The only thing i can think of that hasnt been replaced or checked is the fuel filter. Ive seen where it says that fuel pressure can be a cause. Can you think of anything else it could be???

 

I made an assumption that sense the fuel pressure was "checked" I didn't include the filter, cheap enough, and probably needs replaced

 

My asumption is it's fuel related. Since the fuel rail is using more gas at higher rpm.....

 

wouldnt that cause it to happen on all cylinders

 

DTC 300 is random misfire, could be on all cylinders.

 

Well to end the saga of this engine problem. It turns out it was an EGR valve that was clogged. It was causing random misfire code. The EGR valve has been replaced and there is no longer any error code showing. Talk about one hell of a headache. Thank you Kevin for your help and suggestions.