Hello there folks! One of my very first threads, figured I'd make it a relatively easy one, I hope!

I've got an 07 Hummer that has about 166000km on it, and its got quite the rough idle or 'coughs' when its at a stop light/sign. I bought it in January of 2015 and it didn't have any of these issues, it also had 150000km on it when I bought it. Now, I've seen several videos on youtube that are 'how to' videos involving what sounds similar to my issue with the 'rough idle' and the 'barking' or as one person put it 'farting' or 'coughing' at a stop light.

What I've noticed on my vehicle is that when you shift into drive from park after giving it about 20 seconds after startup it goes from idling at about 500-600rpm or so, and dumps down to like 450rpm or somewhere around there, similar thing happens when I stop at a stop sign and go to accelerate.

People say that it could be a combination of a dirty MAF and a 'coked' throttle body.

Now, I will be trying the cleaning of my MAF and the throttle body tomorrow (Sunday, September 25th). I have the proper cleaners for both and setup for it; I will be removing the TB from the truck to do this, and of course, disconnecting the MAF and TB from their respective harnesses before I go about this.

The main question I have for you folks is this, now that I've got some background info on this.

Because the throttle body on this vehicle is an electronic one, and I've been hearing nightmare stories about GM's and TB's having issues after cleaning. Will I, or -do- I need to preform a "Re-learn cycle" afterward? Or do I just let it idle after making sure the TB is and MAF are dried out and clean?

Also, the reason I ask this is because I have not seen or heard mention of it in any other of these videos on youtube that show 'how to' on doing this.



Any help would be appreciated! Thank you!

 

There is no need for any relearn. Clean away.

You can create problems when you man handle the throttle body butterfly, cranking it fully open, back and forth.... not needed to clean it. Open it enough to wipe out crud all the way around and you are good.

 

Thanks Doc! I did clean it and was very careful when handling the butterfly, have a few new cuts on my fingers to prove it too, lol. Did the MAF sensor clean, cleaned the throttle body, and changed out the spark plugs. My baby runs like a dream now. It didn't even idle like this when I bought it; it was always just under/over the 500rpm tick, now its sitting around 650-700 or so once its warmed up. Engine runs quieter too!