2011 2500hd 6.0 misfire

[shakenfake]

Well if you are getting a code for no cats it is going to screw with your fueling. Maybe not a misfire but it will mess with the fuel 

[casey.mikl]

47 minutes ago, shakenfake said:

Well if you are getting a code for no cats it is going to screw with your fueling. Maybe not a misfire but it will mess with the fuel 

I’m not getting a code for the cats. I’m getting multiple misfire codes. When it misfires, it goes lean on bank one. 

[shakenfake]

Hmmm I am thinking it has got to be a fueling issue on bank one. did you swap injectors? Move all of bank one to bank two? I don't see that you had

[casey.mikl]

32 minutes ago, shakenfake said:

Hmmm I am thinking it has got to be a fueling issue on bank one. did you swap injectors? Move all of bank one to bank two? I don't see that you had

I have replaced all 8 injectors. I have moved plugs between the 2 banks as well as coils and no change. 

[shakenfake]

I'd say check with the noid light next. 

[casey.mikl]

On 10/4/2021 at 5:29 PM, shakenfake said:

I'd say check with the noid light next. 

I got a wiring diagram for the engine harness. I traced the wires to the o2 sensors and they are all fine. I get good solid ground and power to all of them. Bank 1 sensor 1 is holding stead at 1275. I believe that is my issue that’s throwing it all off between the 2 banks. The sensor is good. I took it for a drive and the sensor started reading about the same as all the others and it was fine and then shot back to 1275 and stayed flat. I’m wondering if I have a leaking exhaust manifold and it’s sucking air, thus making the sensor readings wrong. 

[casey.mikl]

I am going to hook up the smoke tester to the exhaust and check for exhaust leaks. 

[shakenfake]

A leaking exhaust manifold doesn't suck air. Check your injector harness with a noid light.

 

It stays flat when it is in open loop I believe. Can't remember

[casey.mikl]

Found some leaks. Both sides of the exhaust are leaking where the y pipe bolts to the manifolds. Had the trans rebuilt so the y pipe was removed. Also found the rear most manifold bolt on the passenger side totally backed out. 

[shakenfake]

Well that could cause it. But it would lose air, still cause it to be out of spec though! The fuel for that side would just be up

 

Glad you possibly found the result

[casey.mikl]

It does have some exhaust leaks. Mainly on the passenger side. I removed the computer and used fiber optic wire cleaner and a brush and cleaned all the connections. Now it’s running good. But sensor one is flat lined at 1275. 

[shakenfake]

Then there is something in the wiring. 

[casey.mikl]

It does have some exhaust leaks. Mainly on the passenger side. I removed the computer and used fiber optic wire cleaner and a brush and cleaned all the connections. Now it’s running good. But sensor one is flat lined at 1275. 

[shakenfake]

Move your B1S1 sensor over to B2S1 and see what happens. 

[davester]

4 hours ago, shakenfake said:

A leaking exhaust manifold doesn't suck air. Check your injector harness with a noid light.

 

It stays flat when it is in open loop I believe. Can't remember

It can.  I know on my truck, which had 6 broken off bolts when I bought it, the O2 sensors indicated mixture was very lean until I fixed them.