I'm new to this forum and posted this somewhere else...not sure where it went. I'll try here in hopes of a response.
I have a 2001 Yukon XL 1500 with the 5.3 V8. It recently started to hesitate after each shift. The hesitation is most pronounced on the 1st to 2nd gear shift and is worse the harder the gas is hit; it is still there but not as bad shifting in higher gears. When it does hesitate, the RPMs go down to about idle and then when it "catches" 2-3 seconds later, it jerks back to acceleration. The codes I get from the system:
P0300 - Random/Multiple Cylinder Misfire
P0449 - EVAP Cntrl System Vent Ckt Malfunction
P0171 - System too lean Bank 1
P0174 - System too lean Bank 2
I had a new fuel pump put in it back in November and tried cleaning the MAF sensor when it started this problem (also tried swapping the sensors with my other Yukon to see if that made a difference - no luck). I have started doing more of my own repair work lately, but up until recently it has mostly been the easier/routine stuff.
The truck is showing its age, but I think it has a fair amount of life left in it at 175k miles. But I would rather not sink a bunch of money in to guessing what the fix might be . Hopefully, somebody has run in to this problem and can offer some advice.
Thanks!
I have a 2001 Yukon XL 1500 with the 5.3 V8. It recently started to hesitate after each shift. The hesitation is most pronounced on the 1st to 2nd gear shift and is worse the harder the gas is hit; it is still there but not as bad shifting in higher gears. When it does hesitate, the RPMs go down to about idle and then when it "catches" 2-3 seconds later, it jerks back to acceleration. The codes I get from the system:
P0300 - Random/Multiple Cylinder Misfire
P0449 - EVAP Cntrl System Vent Ckt Malfunction
P0171 - System too lean Bank 1
P0174 - System too lean Bank 2
I had a new fuel pump put in it back in November and tried cleaning the MAF sensor when it started this problem (also tried swapping the sensors with my other Yukon to see if that made a difference - no luck). I have started doing more of my own repair work lately, but up until recently it has mostly been the easier/routine stuff.
The truck is showing its age, but I think it has a fair amount of life left in it at 175k miles. But I would rather not sink a bunch of money in to guessing what the fix might be . Hopefully, somebody has run in to this problem and can offer some advice.
Thanks!
