02-02-2012, 02:21 PM
I'd say keep it in, there's no downsides for not taking it off, other than you may preserve the part a little more by not allowing it to go through the winter where cars usually corrode at a faster rate. It's not about the sound of the exhaust though, it's really about engine performance. That's why people add a cold air intake. Engines become sluggish when you have too much heat, and operate at the moderately colder temps better. This can also affect engine performance for speed.