2003 Chevy Silverado 6 cyl Two Wheel Drive Manual 91,000 miles
My check engine light came on. I took it to a mechanic that put it on a diagnostic machine. I dont know the codes, but he said that I needed a 02 sensor replaced & catalytic convertor. I could only afford the 02 sensor at the time. Now my check engine light came on again. Does my truck have 2 catalytic converters or one? Is this a expensive repair or should I best take it to a muffler shop for repair? I do not need a smog, just had a passing smog 8 mos ago for DMV.
Woul dhave to look to see how many cats it has, 6 cylinders usually have one. Sounds like you may not have needed the o2 sensor, probably had a cat efficiency code, which is the cat not working up to spec.A muffler shop can do that for you, but you could probably wait until you need to do it for smog check if it isnt hurting performance/mileage