The long term fuel trim codes are around 20 or more and codes are still lean bank 1 and lean bank 2. I don’t have access to a tech2 scanner for a couple more weeks.

 

It did that after you cleared the codes, unplugged the maf, and then drove it for a while?

 

what other code did it have?

 

Only codes that keep coming back are the lean bank 1 and 2. Like I’ve mentioned, when cold it stumbles when taking off. Once at normal temp, I drive it on hwy at 70 and 80 and rides great. Codes always come back weather it’s cold or warm.

 

Ok, you’ve got a bad PCM

 

Damn. That was one of my guesses. Can you use one from another blazer? I could have it programmed I guess if so. More money ugh!!

 

Its not the PCM, Easy test for that is if you can get ANY code reader to communicate with it and clear codes. even cheap Bluetooth ones can do it. you have an Air leak past the MAF sensor somewhere. check the Vacuum hoses leading from the Intake PCV Cover and if needbe take a section of vacuum hose of the right size, plug the end, and then use those to block off the ports on the cover, dont block the PCV itself.

 

if you read through my questions and the OP’s response, the only possibility is a faulty PCM.
Please explain your reasoning for “it’s not the PCM”

 

A Vacuum leak or sticking Fuel pressure Regulator will cause exactly this issue, Sticking regulator chokes fuel feed to the injectors, causing a lean condition, so will a large or decently sized vacuum leak from any part of Vacuum system or the intake. The PCM's used in these trucks are effectively bulletproof. He was able to read and clear codes so the Logic board is not dead, And it would be throwing communications codes if it was not communicating with sensors due to dead pins. my truck has the exact same issue except i know mine is just a pressure regulator i dont want to replace yet.

 

Go back and read the questions again