I have a 2005 Suburban with 5.3 Vortec and 4L60E. I have recently tuned it up with new plugs and wires and oils and filters as well as adding injector cleaner to the fuel tank. Problem recently revealed itself when trying to pass a couple of slower vehicles. The engine lost response from the throttle and started back firing if the accelerator pedal was kept pushed down. I would have to let up off of the pedal for about 30 seconds for everything to clear up and still had uneven throttle response. there has been an engine check light on for quite sometime in relation to emissions evap solenoid or switch which I have changed out along with the O2 sensors but the light remains on. I am also getting a service stability warning. I have extensive mechanical background and can do most testing on my own but need help in pointing to the general area to test. I will be testing the voltage on the TPS and makng sure the MAF sensor is clean. Should I get an engine scanner to evaluate the conditions of the coils?. Normally I would change a fuel filter for this type of problem but this vehicle does not have a fuel filter except for the sock in the tank. I would appreciate some inside help from anyone who has any prior experience with these problems.

 

Just had the codes rechecked and it still shows O2 sensor and emissions evac. Code #'s CO035 x 2, CO196 ?, CO455 ?, PO131 x 2, PO151 x 2, PO449 x 2. The TPS testing did not go as planned as I expected to get a smooth voltage change as I moved the throttle. I did not get any voltage change at all while attempting to test pin B to pin E and pin D to pin H. I do not know where to continue the testing to help me isolate this problem.

 

I am having what i think is the same problem as you. 2002 suburban 5.3. Starts n runsdrives for a while then won't take throttle. I have to put in neutral and shut it off n restart. Then it is fine for a little while then i have to repeat process again to keep driving. Was wondering if you found a fix to your problem?