Chevy Silverado and GMC Sierra Forum banner
1 - 9 of 9 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter · #1 ·
Hello,
I've got a problem that I can't figure out. I have a 2000 4.8 Silverado. It developed a rough idle and loss at power while driving. I checked the dtc and had a p0300 for a random misfire and some O2 sensor codes. I replaced the O2 sensors and cats, then I still had the same problem. I then proceeded to replace the fuel pressure regulator, fuel filter, plugs & wires, and throttle position sensor. I have no idea when else i could be. Any suggestions?
 

·
Registered
Joined
·
3,651 Posts
P0300 is not uncommon with an intake manifold leak. Does the rough idle go away after the truck warms up? Another common symptom.

Also, were the O2 codes P0171/174? If so, those are lean codes also common with an intake leak.

Post more before you throw more parts at it.
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #3 ·
No, none of the codes were for lean. All of them were for low circuit voltage and high temp I believe since I don't have all of the codes infront of me at the moment. I have two codes showing right now one is the random misfire and the other is the abs pump module. Could the problem possibly be a crankshaft position sensor even though it didnt throw thay code? It seems like from reading all of my problems are common with a crankshaft position sensor but just not code for it. the intake gasket is good so I ruled that out.
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #4 ·
Also I fogrot to add I cant get the truck to stay running long enough to get it warmed up. To get it started I have to pump the gas and keep it floored to get it to fire up.
 

·
Registered
Joined
·
67 Posts
Try a Crank Position Sensor re-learn. It can easily be done with a GM Tech ii scan tool or any aftermarket scan tool which you're local garage or service station will have. Show up with a coffee and see what they can do for you.
 

·
Registered
Joined
·
67 Posts
They should still be able to do it. Its common for a rough idle and engine stalling on these trucks due to a dirty throttle body. Its worth a shot before taking it in. Pull the imtake tube off the throttle body and hold the throttle open with youre hand while soaking it with carb cleaner and wiping it with a rag. I do mine once a year. My brother and father have the same trucks and they have had to clean theres a couple times as well. Hope this helps.
 
1 - 9 of 9 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top