Here we go again!!

[LEcustoms]

Still havent had a chance to drop off my truck. hope to get it in the shop next week. The idle is getting worse almost like I have a rediculously agressive cam. My truck has 70k on it as well.

[twenty2]

Well, Im taking it back..... I'll keep you posted on whats up next...

[Rene S. Nielsen]

Actually it might be the cat.

I had the same issue, had a code that said bad MAF (don't know the code, just got the info from the dealer) changed the MAF and still had the same code.

Then into the shop and being in Denmark where the shops don't know wery much about Hummers resulted in me changing the engine (at my own cost) because nobody cared to check the cats.

Regards
Rene

[HumminNBoatin']

Same thing Here. I am now getting the same Codes. I did have my intake tube folded at the throttle. So I pulled it off and boiled it to get it hot and expand. As it was ZERO degrees out last night. After boiling I ran it outside and it slid right on with no fold. I tightend it down and I am still have issues. I guess I will be taking it into the dealer next week.

I really do not think its the cats. Those codes are comming from before the CATS not after. I have already had my CATS replace and the codes for that fix were (System Inefficent) NOT (System Lean). I look foward to your findings. If it was Zero degrees outside I would be all over it

[HumminNBoatin']

Well I have 85K miles on my truck.

This weekend I put my truck on my father in-laws SnapOn Scanner and went throught the whole engine. I could not get it to thow a code for me while it was plugged into the truck. I went through all the injectors and checked for any history of misfires and misfires while running. So that was good news. I left my In-laws house and was getting 7.5mpg. I decided I should change my airfilter. Supposedly the air filter is rated for 100K. But I went ahead and replaced it this weekend. $60 at Autozone. Gas mileage is back up to normal. Truck is running VERY good. My old filter was pretty bad. I could even tell a weight difference when holding the new vs. the old.

Might want to check your filter.

[HumminNBoatin']

Well CE light is on again.....I give it its dealer time.

[twenty2]

UPDATE..I took it to a different shop yesterday because the original shop are idiots!!! They did a smoke check by my manifold and found it IS 100% air intake manifold leak.. I need to get my gasket changed which is causing the slight rpm flutter along with the lean codes.

[LEcustoms]

Didnt have time to go to dealer so checked the intake by the throttle body and what do you know was put on wrong. Pulled it off and re-installed it check engine light is gone and the truck is idling fine now for three days. That was my problem. Good luck to you guys.