Some time back I posted a question about a 2000 Blazer surging or not wanting to accelerate after warmed up. My search has not found that posting however I have found a solution to my issue that may help others. My Blazer started and ran find when cold, always started right away even after up to temp. However after complete warmup, if you shut it off to run into the store and came back out, it would start but not want to go. When you tried to accelerate it would just hesitate and some time you could hear a pop back thru the throttle body. Have had numerous tests done an all showed a variety of different things. Finally found a shop with a test machine that you hooked up and then test drove the car with it hooked up. Again various codes but one strong signal was a lean fule mix on both banks. We unplugged the mass air flow sensor and the problem went away. Performance was not great but no hesitation, we plugged it back in and we had the issue back again. Ended up replacing the sensor and things are working well once again, the old performance is back and the hesitation is gone. Just might help some of you having this issue.

 

Thank you for the update. Did you try cleaning it first?

 

No I didn't bother trying, with 130000 miles and the original sensor I figured it was a waste of time to try that. From what I have read about 70% are replaced by the time the avg vehicle gets to 120000 miles. So I guess its time was up.