Richard Carrino

I learned the hard way yesterday that the knock sensors on the 8.1 are not under the manifold but on the left and right side of the engine. The intake manifold gasket was shot though, so it was worth replacing, along with the throttle body and MAP gaskets. The engine was clean but the intake manifold had a lot of carbon build up. Took some MAF cleaner to the screen and sensor and replaced the air filter which wasn’t too dirty. Upon inspecting the fuse box I found the ENG-1 fuse blown which the MAF is on that circuit. I replaced the fuse and it did not blow so I’m not sure what that was about, I’ll have to watch to see if it blows again. I tested the wire at the MAF sensor connector. The power reads 12v, resistance was good, and the yellow wire read 5.1 v which I read it should be in the range of 4.8-5.2. Looking to tackle the bank two knock sensor today. Anyone else that can shed some light on the issue I’m having or some experience

This truck has had an intermittent misfire since I bought it a little over a year ago. I’ve never been able to solve the issue. Plugs and wires were replaced this year. Scanner was used at a local shop, I don’t personally own it. I’ll inspect the MAF tomorrow and check the wiring. Electric isn’t my strong suit. Any advice on how to properly diagnose? Air filter is worth replacing as well, something I havn’t done since purchasing.

pulled these codes today. Can anyone help me get started on diagnosing/fixing these issues. I picked up a knock sensor, knock sensor wiring harness, and new intake manifold gaskets which I plan to replace tomorrow.

Went for inspection yesterday and failed because they could not connect to the OBD. Tried a mechanic who does state inspection and same result but his scan tool was able to connect and read. Any ideas? One issue I’ve had with this truck (2002 GMC Sierra 2500 Hd) is a bad ground that has caused my cluster to go out. I have cleaned the grounds under the driver door and the ground on the driver side A pillar looks good. Only ground I havnt managed to reach is the one from the firewall to the engine block. My fix for this has been a wire jumped between the two pins on the data port. Dash lights right up after this. Could this be causing the issue? thanks

Once I remove the cluster from the dash do I then disassemble it to reach the ground? Not too familiar with this. It worked with no issues Saturday the Sunday I turned the truck on and it was out again. Could it be the cluster itself?

Got an 8.1 02 Sierra 2500HD that’s been having issues with instrument cluster for a few months now. Whenever I hit a bump the dash resets as if something is loose. All the indicator lights come on and the needles drop and readjust. This started happening after the fuel lines were replaced. I read somewhere it could be a loose ground but I can’t find the thread anymore. I’m guessing something was knocked loose during the repair? Cluster works fine otherwise. Anyone with some experience or input on this issue?