Head Scratcher on 2015 Silverado 6.2L

[SubParMechanic]

I have a 2015 Chevy Silverado with a 6.2L. About 2 months ago I had bent a rod on Cylinder 4. I replaced all the rods, cleaned all the rockers, new lifters (even AFM), new gaskets, plugs, and plug wires. After the truck ran fine for about a week, then threw code P0106, which is a MAP sensor code. And for the life of me I couldn't get the code to stop showing up. If the code is deleted the truck runs perfectly fine for about 30 miles, then it throws the code and has a bogged down, flooded feeling. I've checked everything I can think of and don't know where to go next. 

What I've checked:

Wiring Harness and Ground Connections

New MAP and cleaned MAF

Air intake gaskets and filter

Cleaned Throttle body

Checked Fuel Rails 

Plugs, Wires

Compression tests (all at spec or very close) 

No leaks in intake 

All fuses 

 

After I spent two weeks after work on this thing I decided to take to the shop, they tried a new computer, new sensors, and ran a cylinder leak down test. The truck still is not fixed but I brought it home today because they told me the only option was to send the heads in to be cleaned and new valves. Said the carbon build up was causing this issue but I'm confused as to how that would affect MAP sensor. Especially when compression tests are all right where they need to be. When I replaced the rods I even checked to make sure valves weren't stuck and didn't make contact with head of piston. 

 

Anything help and am open to all options. My next step is to take a look at injectors and to replace/clean the valves myself. 

Edited March 30, 2023 by SubParMechanic
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[Jsdirt]

I assume the engine came out for that overhaul, so your issue is related to that, I'd almost 100% guarantee. A pinched ground or power wire that is held in continuity by one strand could potentially cause this.

 

If it was done in the vehicle, wire pinching is still possible between the head or oil pan. 

 

Since you've got a MAP code, I'd grab a wiring diagram for the MAP and trace anything and everything related to that until you're 10,000% sure every single wire is intact.

 

And I'd avoid that shop in the future ... and spread the word to your friends & family, too.

Edited March 30, 2023 by Jsdirt

[SubParMechanic]

Actually managed to overhaul with engine still in vehicle, but am tracing wires again to double check.  Thank you