I have been looking at an 02 chevy express to buy and it's looks in good shape and seems to drive normal, the check engine light was on and the seller says it's a o2 sensor causing it. my last 2 cars ended up having clogged cats after replacing the o2 sensor. Was wondering what the likely hood of that being the case in this scenario would be?

Prob depends on how long it was left for that long but i asked for 200 less than asking price because of that since he was advertising as it running 100%. if the cat goes thats $200 plus $75 for the o2.



One other thing, when i drove it i couldn't hear the engine change rpms when manually downshifting. I was going terribly fast but about 25-30. (had to stay in a apartment complex) Didn't show if shifting is a common problem with these or if it was just me