Problems
Thread Starter
TECH Apprentice
Joined: Sep 2013
Posts: 355
Likes: 19
Problems ms
Hope this is the right place, I have a 2005 chevy 2500 HD with the 6.0. I get PO300 code constantly, clear it and when you get to 50 or 55 MPH the light starts flashing. Also I get cat codes and knock sensor codes at random, plus it'll go in limp mode and won't accelerate
unless you pull off and shut it off for 3 minutes or so. It's done that 4 times lately but it may go 2 mths before it does it again. It runs great, no misfire that I've ever felt. It has new knock sensors, intake gaskets and a GM crank sensor. Anyone have any ideas? I would really like to figure out this 300 code. Also it uses some oil, did the 05 get the screwed up valve cover that pulls oil through the pcv? I put a new pcv in it.
Hope this is the right place, I have a 2005 chevy 2500 HD with the 6.0. I get PO300 code constantly, clear it and when you get to 50 or 55 MPH the light starts flashing. Also I get cat codes and knock sensor codes at random, plus it'll go in limp mode and won't accelerate
unless you pull off and shut it off for 3 minutes or so. It's done that 4 times lately but it may go 2 mths before it does it again. It runs great, no misfire that I've ever felt. It has new knock sensors, intake gaskets and a GM crank sensor. Anyone have any ideas? I would really like to figure out this 300 code. Also it uses some oil, did the 05 get the screwed up valve cover that pulls oil through the pcv? I put a new pcv in it.
Joined: Apr 2006
Posts: 3,909
Likes: 1,158
From: Grand Rapids, Michigan
I have a 2006 LQ4 in a 2500 HD Silverado. Was getting the P0300 code all the time at highway speeds. Turns out I needed to do a crankshaft variation learn. I did that and haven't had a problem since. I will say, I had to to knock sensors on mine and aftermarket ones SUCK. I had some GM ones on my blown up LS1, so I installed those with zero issues since. Get a good scanner and do a crankshaft variation learn. It might be the issue.
Thread Starter
TECH Apprentice
Joined: Sep 2013
Posts: 355
Likes: 19
I didn't use gm knock sensors, I should have. When I put the crank sensor, factory gm, I tried relearning the sensor and it won't relearn. It says rpm not reached or something like that, it's been awhile. It's a snap on scan tool. May try again or find someone with a different scanner.
On my 2006 2500HD I was getting P0300 at 100K and 180K miles. Doing a tuneup, etc didn't resolve. I did a CPS relearn in both cases and the issue was resolved.
The engine is a stock 6.0.
The engine is a stock 6.0.
Joined: Apr 2006
Posts: 3,909
Likes: 1,158
From: Grand Rapids, Michigan
I didn't use gm knock sensors, I should have. When I put the crank sensor, factory gm, I tried relearning the sensor and it won't relearn. It says rpm not reached or something like that, it's been awhile. It's a snap on scan tool. May try again or find someone with a different scanner.
I used a chinese Xtool D7, I had to retry also. Reving it to the fuel shutoff gave me pause even though it's only 4K-ish or so and I didn't rev it high enough the first time.
Second time was fine and you can just hear the rpm's start to fall off.
Second time was fine and you can just hear the rpm's start to fall off.
