Quick question (so I don't have to crawl under the car and phisically measure): I am thinking of replacing my muffler with a better performance muffler so........what is the diameter of the exhaust inlet to the muffler?

 

Since you have the 2.4 in yours the diameter should be 2 1/4" on the stock pipe so you can size your inlet to that.

 

You won't find one. The OEM is pretty efficient. Years ago I dyno tested the stock muffler vs. a straight through Magnaflow. Absolutely NO gain!
Did sound nice, though.

 

You're right JoeR, any performance gains or mileage improvements with a performance muffler/exhaust system are so small they really don't even get out of the "statistical variable" category.

But that being said, there is just nothing like the bark and crackle of a really nice system, you might not be any faster, but you sure do feel and sound faster.

 

Thank you

 

That works for me, some sound like fart cans, or angry bees..,

 

If you are looking for performance with the exhaust system you should start with the header and downpipe. I put on a high flow header and 3" dp a while back and I noticed gains that I could actually feel. No dyno to back it up but it was very obvious that top end power was gained as well as better fuel economy. The last thing I did was the muffler. With a high flowing header/dp the stock muffler will become restrictive as the exhaust system would be far more efficient. At that point you would undoubtedly throw a CEL and would need a tune. My tuning logs showed my car was very lean after putting on my magnaflow so I believe a dyno would have shown gains, but that is only because of the header and down pipe efficiency. There are some threads either here or on the cobalt network showing the inefficiencies of the header and downpipe.