My stangs been getting pretty crappy gas mileage.. 15-18 mpg tops. I just had it in the shop, they replaced the IRCM's which I thought would fix the problem but didnt seem to do much. Its blowing alittle smoke on acceleration and smells real rich. What should I try first? O2 sensors? Someone told me to just replace the 2 before the cat. Is that true? Thanks for any help,
-Franklin '96 Cobra