So I can smell a gasoline smell when i walk behind my truck while it's running. I haven't had any backfiring or anything but the fact that i can smell gas worries me. I also have been getting much worse than usual millage so it sounds like I'm running really rich to me. I was wondering how to adjust the efi so it won't be as rich or if i should even try messing with it. It's a 90 22re 4x4 pu.

 

The EFI adjusts on its own. Are you sure you do not have a leaking fuel line? The ones at the tope of the tank are prone to rusting out and leaking.
You may have a vacuum leak as this will also cause. If the computer is sensing a lean condition because of the leak then it will richen the mixture. Change your air filter and O2 sensor.

 

I have a cold air intake that i custom built. would that make it want to run rich. I could see the o2 sensor doing that but i never thought the air filter would make it run rich. It could also definetly be the fuel lines. I havn't ever touched them and it's not exactly a new truck. I'll have to try and get under there. I really don't want to end up with a fire.

 

The intake shouldn't make you run rich. If anything, you'd go lean since the colder air is more dense and it would need more fuel to compensate for the extra air.
When was the last time the timing and a tune up was done? How do the spark plugs look now?

 

uhhh.... yah, probably about 60,000 miles ago. I replaced the plugs about 2 years ago but i haven't checked them recently. I've been meaning to for a while I'll check those and then come back and let you know what they look like.

 

get under there with your sniffer and see where its coming from dude!