2002 2.4l

I have a 2002 2.4L 4-cylinder Frontier. I was wondering, what is the best way to improve the gas mileage and the horse power, but without spending a lot?

hp and gas milage dont mix, lol ur pretty screwed, but a good exhaust will help, and a cold air intake will be the cheapest. so try those two first...but thats about it unless u can get a really good chip.