Marcos Beltran
OBS Enthusiast
Ive been having hesitation problems since ive bought this truck. Its a 96 gmc v6, 4.3. Got it running really well for the last month and a half recently started to hesitate slightly. Put on my scanner and the short and long term fuel trims are all over the place. Sometimes the short term is high, sometimes the long term is high but never really a pattern thats consistent. During the initial acceleration is when i get the most erratic readings. While cruising it stabilizes for the most part and down to normal values. I did find that one of the down stream o2 sensors, the one right in front of the catalytic convertor is not working properly. It idles at around .045 to .070 and never goes higher. But on the initial acceleration it will sometimes jump to .800 but will go back down and will never reach above ..150-.200 during cruising. My question is could this be causing my problem im having now? Reason i ask is cause ive heard from people and read of people deleting their catalytic convertor and having no issues with the way their truck runs. Although they could be exaggerating, but i thought only the 2 upstream o2 sensors affected the driveability.