Auto Parts: Exhaust, catback exhaust systems, stock air filter

Question
Hi Mike - I have a 2005 Saturn Ion 2.2l. I'm planning on buying a catback exhaust system for this. Catback exhaust systems as far as I know for my vehicle only goes back as far as the Catalytic Converter. My Questions is will that then not make any difference in horse power? The Cat is still only going to allow what it was in the first place right? Just because what’s after is 2.5inc that cat won’t step up performance will it?

THanks,

Greg

Answer
    In newer cars, like yours, the design of the catalytic converter is much more sophisticated than in older cars.  When they were first introduced, converters added restriction to the system, and the manufacturers figured that it was something they had to live with.  But, since the advent of really efficient EFI and engine controls in the early '90's, the converter really doesn't strangle the engine much.  A cat-back performance exhaust is probably the most cost-effective way of increasing engine output.  The bonus is that it will sound better, too.  If you wanted to do something else, an air intake system might help, as well.  Although, nine times out of ten you will get just as much of a performance increase from replacing the stock air filter with a K&N element.  Any more increases beyond that are going to be very expensive.  If you really need to go faster, you might want to consider trading up to the supercharged version, or getting into something with twice as many cylinders.  The Ion is a neat little car, though, and you might consider some handling upgrades instead of more power.  You won't be killing them at the stoplights, but they'll have a hard time sticking with you through the twisty bits.