Originally Posted by crussell85
I have a 2002 Chevrolet Impala LS with the 3800 and around 250,000 miles. The exhaust resonator on my car is rotted out and I hate the sound of it, it is just a loud exhaust leak. I checked on the price of a replacement resonator and it was around 75 bucks. I am wondering what would happen if I just cut out the resonator and replaced with a piece of 2.25" pipe? With the car get louder? Will my fuel mileage change? Will performance be affected? And the most important question to me is, will it change the lifespan of the engine?
Being as how the resonator is downstream of the O2 sensor, there will be no difference in the engine lifespan if you were to remove it. It will be louder than with the resonator in place, but not as bad of a sound as the resonator w/a hole in it or it leaking exhaust.
There will not be any difference, performance-wise if you remove it, if anything there will be a little bit less backpressure and it might actually run a little bit better, same w/the mileage- it will be either the same or a tiny bit better. Likely as not, the difference will not be measurable w/o very careful testing.
The small amount that the removal of the resonator affects the exhaust backpressure will be easily compensated for by the ECM, so if you want to replace it w/a length of pipe, I see no problem w/doing that.
I'm not an authority, but I do not believe this will have any affect on the smog police, either- but you might want to check on this first if you have inspections where you are at.