I have a 2001 2500 with the 5.9. I just got rid of my 92 dodge stealth. ANy help with the mileage thing? Nothing big but i wouldent mind hearing some ideas

single out 3" exhaust or dual 2.25" out's will help, K&N FIPK II should also help.

Looks like you're new, Welcome to the site. If you have over 70K to 90K miles on the truck, you might want to replace the upstream oxygen sensor(s). Like spark plugs, they start to go degrade over time. You might want to post some more information, like mileage, gear ratio, tire size, etc. for your truck. How long have you had the truck?

Welcome! First I would suggest a general tune-up. Get a good cap and rotor with brass contacts (NAPA has them), good plug wires, and some good plugs. (lots of us use Champion Truck Plugs). Don't get the Bosch Platinums or other "fancy" plugs - they do not work well in these trucks. A K&N drop-in air filter will also help. Synthetic oil and gear lube will help also. From there - you can read the threads and see what everyone else is doing for further upgrades. Post a "signature" with your truck info - that allows us to know what you have and we can help more.....

Adding performance intake and exhaust parts will slightly increase gas mileage and power overall, but nothing to raise a ruckus about. Having poor gas mileage is part of owning an engine such as the 5.9

Bed covers can help a ton too.[sm=trust_me.gif]

Also if you haven't done so already check your plenum gasket and see if it is leaking. If so that will hurt your gas mileage and power alot.

How do you check the plenum gasket?

Took down your throttle body. Theres theres alot of oil in the bottom its probably shot. Some oil is normal is it comes it from the PVC. Steve also recomends to get a small mirror and check in all the corners for oil.

ok i've got a story about those bosch platinum plugs...

ok my friend who drives an 88 325i coupe put some in and about three months and like 10k miles maybe, he pulls them out to do a compression check cause he was down on a couple cylinders, not too bad but not too good, anyway, he pulled the plugs out and they were covered in this white crap looked like a calcium build up or something. he was like WTF!!!! pissed cause he spent like 6 or so bucks for each plug. had to replace all the plugs as they were all covered varying in degree from barely a spark to nearly full. replaced them with some lower grade plugs and they are workin a hell of a lot better, seems like it has more power than before.

anyway, don't always trust that more expensive stuff is going to work better. it doesn't always. at least with the sparks anyway.