Wednesday, May 24th, 2006 AT 4:39 PM
I got a 99 sc2, well it kicks when you hit about 50 mph, I have been told it was the o2 sensor. Replaced it. Thought it was the spark plugs. Replaced it. Replaced the battery. Replaced the Serpentine belt along with tensioner. I Do not have a clue what is going on. Engine sounds great and idles fine. Before I replaced anything I drove to an auto parts store to get a free diagnostic done on it, code "P0420 Catalyst Efficiency Below Threshold" so any clues?


