I have an 07 Tahoe with aprox 116,000 miles. Volant cold air intake, Volant cat back exhaust and a computer tuning. Have had surging issues with it for about 30k miles. Usually about 45 to 60mph. You can feel it slightly surge and see the rpm do the same. Now for the last couple weeks its got an idle issue and hesitates off the line. Doesnt matter if it is in gear or park, you can feel it and see it on the tach. Have checked wires, removed throttle body and completely cleaned. Also cleaned manifold as far as my arm could reach. have been receiving a check engine lite but on-star says it is for a tank sensor ( gauge doesnt always read right) What am I missing? Thanks.

 

Welcome to the forum.

Were the plugs replaced at 100K miles?

 

65,70k. Plugs and wires

 

Are you sure it is not the way that the motor just normally runs? My father has an 06 silverado and I have an 07 tahoe. Both 5.3L, and both of them have a little hiccup when at idle, it freaked me out at first til I realized that most of them do this. It just doesn't run as smooth as a lot of car motors do.

I did read somewhere though, that one guy installed a tuner on his and increased the idle to 750 rpm and that seemed to make it better.

 

Might want to check and clean the Idle Air Control (IAC valve)

 

At what mileage was the computer tune done?