95 t'bird exhaust modification

Asked a mechanic why there are what looks like 5 cataletic convertors on my car and can I put maybe some flowmasters in the place of ....? He said that the exhaust reports back to the computer to make the mixture lean or rich and if we change anything that my mileage would go from approx. 25 mpg to 10 mpg. Just wanted my tbird to sound like the v8 it is....Thanks, Matt

Your mechanic is clearly not any sort of exhaust specialist and doesn't really understand modern emissions systems.

You can replace your mufflers with any other mufflers you want to, including flowmasters. You could even completely remove them and your computer would be none the wiser.

However, yes the car would throw a code if you removed the catalytic converters and it would negatively affect fuel economy. However, they make little things called MIL eliminators that are plugged in in place of the O2 sensors that make the code go away and the car operate normally.

Also, note that it is illegal for a shop to remove the catalytic converters on a street-driven vehicle, so if you want to remove them you'll have to do it yourself or find a shadetree mechanic to do it.

Thank you for the advice on the exhaust. There was a mechanic that I talked to that said that he could tap into the new exhaust and re-install the original O2 sensor and that there would be no info change to the computer. What do you think? He says he does this all the time with no ill effects.

yes, that would work too