I have a 2005 Si 5 speed hatchback with approx 138000 miles on it. last year I replaced the Cat and the downstream 02 sensor. It hasn't even been a year, and now I have a bad upstream 02 sensor and according to the shop a bad Cat Converter. My questions are, If I have a bad upstream sensor, will the cat throw a code also, & if I do not replace the 02 sensor or the cat will it cause any damage? I am thinking of just replacing the sensor to see if that works or will I just be wasting my money? So far the car seems to be running just fine, no decrease in mileage or performance. Any ideas would be helpful.
Thanks,
John
Thanks,
John