AFM

[Charlie207]

Yes you're right. I'm going to be doing the swap on my sierra which is 14-18 not 15-20 like the tahoe and yukons

Ah, this is the 07-14 GMT900 forum, so I was confused.

 

[buckwild27]

Ah, this is the 07-14 GMT900 forum, so I was confused.

Yeah I have a tendency to miss that part on my phone.

 

[dmad1]

For the time being till you get it tuned unplug the sensor wire in the brake booster vacuum line. It will prevent it from going into 4cyl mode. You will have a check engine light on because it can't find the sensor, but it doesn't cause any Drivability, issues. That sensor is what tells the truck that it is okay. And has enough vacuum to go into 4 cylinder mode. Then when you go to get it turned off in a tune you can plug it back in. Also if you change out the cam and lifters then you can delete the vacuum pump which also has it's downfalls because you won't need it anymore after you eliminate the AFM.

Would you mind sending a pic of where the sensor wire plugs into the booster?

 

[buckwild27]

Would you mind sending a pic of where the sensor wire plugs into the booster?

07-14 booster it's the same for the 15-20 guys too.

 

[dmad1]

Great pics. Thanks a million!
As a footnote, when it misfires and or sets a code, does your transmission act up? Local shop wants to replace lifters and tranny. Huge $.

 

[buckwild27]

Great pics. Thanks a million!
As a footnote, when it misfires and or sets a code, does your transmission act up? Local shop wants to replace lifters and tranny. Huge $.

I can’t answer that I've not had that problem.