We have a '09 Tahoe LT with a 5.3 It started stumbling at idle and also on the highway when passing. Has anyone experienced these issues and if so, what was the solution? The Tahoe has roughly 117,000 miles on the odometer

 

Did it show any codes? Perhaps a bad coil, or spark plugs need changing?

SD

 

My 2002 Tahoe with the 5.3 was stumbling similar to to yours. First I changed the fuel filter and when that didn't help, the fuel pressure regulator and that did the trick for me.