NO I suspect very little. You didn't mention cat back exhaust or an X pipe. Many times people fail to recognize the importance of new o2 sensors for performance. They tell the engine to run correctly based on what they read. old ones fail to read right and actually detune a motor. Good wires, top plugs clean throttle body or later a larger one along with a reprogramming and that exhaust work and you'll have seat of the pants gains!

A K&N air filter will add power but only at high RPMs. Under normal driving you will see no difference at all. A high flow exhaust will add around 5 h.p. depending on that car.

At best 5HP, and that's being optimistic...think about it...some of those motors they would dyno are 5-8 *liters*, what do you have, 3.8L? Which do you think would see more of a gain?

All cats were "high flow" by 2001, it gave you nothing.

I checked the K&N web site and they do say "increased horsepower" - but are very careful (elusive?) not to say how much.

I read one comment from a user that *said* their car was dyno'ed and increased close to 24%. I think that's a bit optimistic, but hey, who knows?

Check out K&N's site to see what it says for YOUR car (you didn;t specify which engine your Grand Am has...)

http://www.knfilters.com/search/appsearc...

(Personally, I don;t put much stock in bolt-on performance mods either - but - an air filter you never have to replace - that is freer-breathing than stock? It may just work as advertised!)

You might get as much as 10 HP total. More noise than power.

Probably a loss in power.....all the extra power gains is just make believe.

Hi, I have a 2001 grand am gt ram air and it has a k&n drop in and a high flow cat. I was curious what a realistic power is from that. Im thinking around 3-4 percent gain over stock, does that sound accurate?