What did you do to your NNBS GMT900 Tahoe/Yukon Today?

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

j91z28d1

Full Access Member
Joined
Feb 28, 2022
Posts
3,226
Reaction score
4,009
guy at work has a 08 truck with the 4.8 in it. tapping like crazy, heard it across the parking lot at 430am. I walked over to talk to him, he's like it's been like that forever. revs it up and it goes away, idles for a bit and starts tapping again. 200k and he says the truck 4.8 never had the afm. truck didn't even have oil pressure gauge on the dash and he's never looked. just when it gives up its going to the junk yard. not worth fixing.


kinda wild just drive it around tapping. he said it sometimes goes away for months at a time and then comes and goes.
 

Doubeleive

Wes
Supporting Member
Joined
Nov 7, 2017
Posts
26,522
Reaction score
39,911
Location
Stockton, Ca.
guy at work has a 08 truck with the 4.8 in it. tapping like crazy, heard it across the parking lot at 430am. I walked over to talk to him, he's like it's been like that forever. revs it up and it goes away, idles for a bit and starts tapping again. 200k and he says the truck 4.8 never had the afm. truck didn't even have oil pressure gauge on the dash and he's never looked. just when it gives up its going to the junk yard. not worth fixing.


kinda wild just drive it around tapping. he said it sometimes goes away for months at a time and then comes and goes.
lol, my 03 silverado that I sold to my sister does the same thing 284k+ on it, taps at idle after sitting for a minute and comes and goes usually months at a time, it's good truck, she refuses to sell it back to me.
 

Doubeleive

Wes
Supporting Member
Joined
Nov 7, 2017
Posts
26,522
Reaction score
39,911
Location
Stockton, Ca.
Rank amateur here but is it possible the ecm is misreading the MAF input?
dealer said they took a look at it has high exhaust pressure, suspect 3rd cat is clogged, so they said get that looked at and put the stock airbox back on it and bring it back and then they can get more accurate readings
 

Writefast

Full Access Member
Joined
Dec 23, 2023
Posts
149
Reaction score
180
dealer said they took a look at it has high exhaust pressure, suspect 3rd cat is clogged, so they said get that looked at and put the stock airbox back on it and bring it back and then they can get more accurate readings
Hopefully that fixes everything.
 

j91z28d1

Full Access Member
Joined
Feb 28, 2022
Posts
3,226
Reaction score
4,009
lol, my 03 silverado that I sold to my sister does the same thing 284k+ on it, taps at idle after sitting for a minute and comes and goes usually months at a time, it's good truck, she refuses to sell it back to me.


I'm surprised they last so long tapping like that.
 

Forum statistics

Threads
132,766
Posts
1,873,892
Members
97,601
Latest member
lefty51
Top