I'm wondering if someone could give me an idea what to look for here. I drive a 98 s vin. I used to get 18 mpg on the freeway. I but a F vin intake on, turbo master (home made) and had the cat and muffler removed and pipe welded in. So no the last time i checked i got 13 mpg. Oh yeah and that was after i put the factory turbo control back on. Is this what i can expect from this set up. If so i'm putting the turbo master back on so at least i get power for all the fuel i'm using.

Any smoke? SES Light?

Winter fuel mix = less mpg (not 5 though, more like 1-3 depending i guess).
Cold weather = more idling (for more people to warmup)

Both those contribute to lower mpg. Whether they add up to 5mpg I'm not sure.

Any smoke? SES Light?
No smoke anymore. the light was on but now it went off.

Any smoke? SES Light?

x2 I know you put an F intake on, but I didn't see anything listed about an ECM or anything setup to ignore the EGR.

i plugged the hoses. what should i do with that stuff

It has 3:42 or whatever is the lowest rear end gear ratio. So i figure i should be pulling in way better mpg.

so any ideas

Not sure what temps you are seeing out there, but here it's -25 to -30 and my mpg are really down also. My fix is keep to filling up and keep smiling. Just think how much new truck payment and depreciation would be.

im wondering about that EGR stuff that you removed and just plugged.

x2 I know you put an F intake on, but I didn't see anything listed about an ECM or anything setup to ignore the EGR.

I agree too. You put a different intake on (from an F series) which doesn't have any EGR crap as far as I know. You need to update the PCM to recognize the bypassed EGR BS. IMO.

I just got back from Lake Tahoe, a ~500 mile drive from LA each way.

On the drive up... I got about 16MPG.

I drove about 200 miles while I was there and my MPG's dropped to less than 14MPG. Daytime highs were in the low- to mid-40's. Overnight lows were in the low- to mid-20's. I didn't have any place to plug in the Suburban, so it was relatively hard to start in the mornings... much longer crank times, LOTS of white smoke and then a rough idle for 10-15 seconds, while all the cylinders came online. (My GP's are of unknown vintage, so I think they are shot.)

On the trip back, I got even better MPG's than on the trip up. I haven't done the math yet, but the position of the fuel gauge is indicating that I should be getting 1-2MPG's better than the trip up... so 17-18MPGs.

I think for me the operating temperature is the key.

While up there for the 200 miles, most of my drives were to the ski slopes and back, too short to allow the engine to get to 185F. Plus with my starting issues, I had MUCH longer idle times... sometimes 10-15 minutes, twice a day.

I'm going to swap out my injectors (also of unknown vintage) and GP's and hope that fixes the issues for next year's trip.

I hope this helps.

Thanks and take care.

More later...

Z.

I'm wondering if someone could give me an idea what to look for here. I drive a 98 s vin. I used to get 18 mpg on the freeway. I but a F vin intake on, turbo master (home made) and had the cat and muffler removed and pipe welded in. So no the last time i checked i got 13 mpg. Oh yeah and that was after i put the factory turbo control back on. Is this what i can expect from this set up. If so i'm putting the turbo master back on so at least i get power for all the fuel i'm using.

1998 k1500 S vin, 180,000 VIN F intake general grabber at2's 265/75/r17



Are you sure that your speedo is correct, did you check it after you put them 17" rims & tires on?