my engine light is on and has been for a little while now. Thought it was the 02 sensor. However, just recently I've notice a slight loss of power. The mpg is still ok but, while climbing a grade, I stomped on the accelerator and the rpms went up as it downshifted, but it was like a clutch was slipping. I gained very little speed, so I let off on the accelerator and the engine light started to flash. I thought the fuel contributing to the problem cause a got a pinging noise too. I use 87 octane. My car has over 80k, so it is out of warranty. I commute 120 miles day. Anyway, the car feels like the cat might be the problem. So, did you say the dealer replaced yours at no additional cost? I can't afford buying a car every two to three years. I'm not sure I can afford a new cat. From what I have read, the defective cat seems to causing a lot of problems.