Cheap upgrades to engine?

-i have a 1999 jeep cherokee sport 5 speed manual. i would like to spend as little as i can but im looking to add somewhere around 15-20 hp, not much just a little extra umph. i was thinking a cold air intake? any other suggestions?Nay Bro is right on the money. cold air intakes can cost a bit(especially if you get a K&N), but they're definitely worth it when you have a larger displacement engine. if you have the 4.0, you'll probably gain about 5-10hp with the intake alone...plus, it'll sound a hell of a lot better. aside from that, just give her a basic tune-up(oil change, spark plugs, clean out the fuel injectors, etc). engines gradually lose power as they go through more use. some basic maintenance will definitely free up some ponies that've slipped away.



@Pete M: sorry buddy, but Jeep didn't have performance in mind when designing his throttle body, intake, sensors, etc. they had passenger comfort in mind, which is why his muffler doesn't sound like a top-fuel dragster. most Americans treat cars like appliances, and manufacturers are forced to make things a bit quieter for the average consumer. this results in silencing both the intake and the exhaust of a car, which ends up choking your engine. cold air intakes don't offer much of a power increase, but they're still better than stock.



i've had a cold air intake on my Integra for 3 years now. my ECU is operating perfectly, i've had no engine issues whatsoever, and my dyno rating with the catback system is up to about 195hp now(170 stock). sorry, but you don't know what you're talking about.Cold air intakes are old technology.



They worked on carbureted engines but with today's computer controlled, fuel injected, sensor equipped engines they end up causing you a lot of work for zero increase in power.



Your Jeep, engine, fuel injection, air intake and sensors all were designed with best performance as their goal.



If you change one of these components it will affect all the others since the computer is programmed with the original design as it's benchmark.



Your best bet would be to go to a speed shop and talk with the guys there. They should have some current information that could be of use to you.



There is no proof that any of the companies that sell cold air intakes have been able to back up their claims.
A DIY cold air intake, change your spark plugs, change the oil and filter, make sure your timing/tune is in spec. And, if your local law says so, remove the catalytic convertor for better flow.



This should net you about what your looking for. You will be amazed at what a good service and tune can do....
Rear end gears are the best bang for your buck. Although being 4wd you'll need to replace the gears in both the front and rear differential.