Not your typical tune-up parts

[dub02gpgt]

Hello all,

I have been noticing that my mileage is pretty poor 12.5ish no matter what and i'm beginning to think a tune-up is in order. i have a 99 and it has a motor with 16k on it, but the rest of it is around 147k. O2 sensors, or catylitic converter or something else that might make a difference??? i believe that the plugs, wires, cap, rotor, and distributor are only 16k as well. plugs look like they should be replaced almost like there's tar above the threads. i thought the fuel filter was also replaced at that time too but idk. also if the intake has 147k on it should i "clean it" somehow? vehicle is bone stock and i seem to have noticed a solid 1 mpg by going from 87 to 89. Any help would be greatly appreciated...

 

[99COOP]

Yea i would do just what you mentioned above. O2 sensors, even when their not completely shot can still cause poor mileage, as well as a gunked up Cat. Fuel filter can make an improve, plus its very cheap and easy to replace. Cleaning out the intake can make a big difference as well, check your air filter while your at it.

 

[bowtiefreak]

most guys on here are happy to see 12.5

 

[cmcarr85]

I would love to see 12.5 hopefully with these gears I will...

Will o2 sensors and bad cats cause that big of drop in mileage? My o2 sensors are bad by the cats and my cats are shot but I havent replaced them yet. Will it make that big of a difference?
I wanted to get rid of the cats and get those dummy o2 sensors to fix it. Bad idea?

 

[jmildoc]

Ouch. I have the 6.0L 2500 with slightly larger tires than stock, and I average 14.5. I have an intake and exhaust though. the exhaust alone gave me 1.5. and intake about 1mpg

 

[99COOP]

most guys on here are happy to see 12.5

This is very true... (i would be)

I would love to see 12.5 hopefully with these gears I will...

Will o2 sensors and bad cats cause that big of drop in mileage? My o2 sensors are bad by the cats and my cats are shot but I havent replaced them yet. Will it make that big of a difference?
I wanted to get rid of the cats and get those dummy o2 sensors to fix it. Bad idea?

Yea 02 sensors will make a difference, not a huge difference but probably noticeable. Clogged up cats will really strain the motor though, so if yours are shot i'd replace them and you will see a big difference in engine power, response and probably mpg's while your at it. Also when the time comes for any of our trucks, mine included go with the magnaflow highflow cats.

 

[roadrageror]

SEAFOAM!!..I dunno,its cheap and cant hurt..

 

[dub02gpgt]

got a part # for the magnaflow cat? Where would i put the seafoam? is there a D.I.Y./how to for it?