id say buy another truck.

notice..."another" not a replacement.

 

well,, around town, my truck when it was stock, got ****ty azz milage, but around highway i had about 15... these trucks are not gas sipping yotas, if you can aford it, get a new one, if not, just check inside the intake for oil, and you will probably notice the oil build up, thats your plenum, change that, and your good, yourtll get alot better milage, as long as you dont do 0-60 checks every stop light...

 

+1, plenum is blown, pre-cat o2 sensor is bad because of it, and the catalytic converter is probably shot because of the plenum too!

 

I have the same problem I last got 280miles on 30gallons..I will look into getting a new cat and o2.
Is that o2 the upstream?

 

Yeah, that's the pre-cat sensor.

 

yes just before the cat.

thanks for the info Z, i never thought of the oil gettin guncked up in the CAT. i think im gunna hollow it out...or go to summit and get the high flow

 

yep.

a 98 2wd should average (city/highway) about 14-16mpg if you drive sensibly (not stomping on it all the time).

if you don't get one of these http://www.hughesengines.com/Index/p...4&partid=22220 then your plenum gasket will blow out again. probably in less than 50-60k miles.

 

+1 on plenum, my mileage sucks b/c of that

and the fact that i'm driving a truck with a Magnum, and have a heavy foot

 

exacally, it will save you money in the long run. ive noticed way better performance with mine