Mr. Demeanor

2005 Hummer H2 6.0 with TRailblazer SS intake/TB/injectors, headers, full exhaust, and custom tune.

Last year I had a knock sensor go out so while the intake was off I had the shop swap it for the Trailblazer SS setup. It turned into a nightmare as the shop kept frying ECM's and my truck was there for almost two months.

Finally got the truck out of there with a preloaded ECM from Blackbear then took it to another shop for a tune that went well.

Now I am getting a CEL so I scanned it and saw mass airflow and knock sensor low voltage again :-(

I cleared the codes and it took a couple days but when the light came back on I pulled over and immediately scanned it. Same two codes.

It seems odd that I would get both codes at the exact same time.

Any ideas other than horrible luck?

G Atsma

Just a weird thought.... check and see if those sensors wires run together and might be chafing against each other somewhere. Worth a shot...

Mr. Demeanor

Just spoke with Glenn at Glenns Auto Performance where I bought the intake. He said both of those circuits come off the same side of the harness and to check the grounds at the back of the heads.

G Atsma

I'm surprised I didn't use my best line, "Check ALL grounds!". I'm slipping.... lol