Scott Martin
Newbie
Hey cool dudes.
My 99 Yukon with 280,000 miles has the P0300 and P0430 codes, it runs a little rough at idle but nothing bad, it has normal power and still gets pretty good gas mileage. When I park it there's a strong odor of gas but no obvious leaks, when I get on the highway it will sometimes start misfiring at around 50-60 mph and I know it's misfiring because I can smell exhaust or burnt carbon or something. I put a full tune-up on it 2 years ago along with bank 2 upper o2 sensor... I know the P0430 code is bank 2 catalyst so should I go straight to the downstream 02 sensor first or should I check the timing and what not?
My 99 Yukon with 280,000 miles has the P0300 and P0430 codes, it runs a little rough at idle but nothing bad, it has normal power and still gets pretty good gas mileage. When I park it there's a strong odor of gas but no obvious leaks, when I get on the highway it will sometimes start misfiring at around 50-60 mph and I know it's misfiring because I can smell exhaust or burnt carbon or something. I put a full tune-up on it 2 years ago along with bank 2 upper o2 sensor... I know the P0430 code is bank 2 catalyst so should I go straight to the downstream 02 sensor first or should I check the timing and what not?