dirtdiggler02

iTrader: (7)

I have a predator installed, but i descreened the maf like 7-8 months ago and now i think this could be most of the problem. Does anyone have a screen to sell???

CHEVRACER83

Working with GM as i do, i know we have alot of people with trucks who remove the screens..... it is a very expensive mistake. there is very little to gain from it. there is more to lose by doing it. I dunno when the last time you looked into a MAF for your truck... ORIGINAL LIST PRICE IS $240.83
GM PART # 25318411

My suggestion if you are looking for gains out of your MAF and taking the screen out has already been done.... get a granetelli motorsports MAF from what we have seen come through that is the best one with the least amount of problems weve seen come through our shop. and the gains are pretty amazing. im not guaranteeing anything, i just know that is the one from my experiance that has had the leasst problems.

dewmanshu

iTrader: (4)

you have no codes? usually such horrible mpg is a direct result of your o2's telling the pcm something that isn't true. pre-o2 exhaust leak? clogged cats? don't worry about the screen too much, if anything it should cause a lean scenario. I mean, you can put a stock maf back in (which i'd suggest), but i doubt the de-screening is causing such horrible gas mileage, maybe, but a loss of 9 to 10 mpg's? how is the power? nothing changed before you noticed the mpg probs? did all of a sudden it start getting sluggish and what not?

BlackGMC

iTrader: (31)

Not trying to sound like a smart *** or anything, but when you added the 24's did you update your tire size in the computer?

dirtdiggler02

iTrader: (7)

Hey guys, Thanks for all the info. I am planning on getting a factory screen for my mass air. I did not notice any gains at all when i took it out. I don't have any codes and the truck runs ok(no bog or lack of power). I did not think that changing the tire size on the predator would do anything other than correct the speedo. What else will it change? I am willing to do anything to get a little more out of each tank of gas. If there are any more ideas or any more advice, i'm all ears. Thanks again...

LS1TRUCKGUY

iTrader: (7)

how many miles are on the truck? new plugs/wires? dirty, or over-oiled air filter? fuel filter/fuel system flush? recalibrating for the big tires/wheels will also make your odometer read correctly...along with your speedo.

dirt track racer 81

iTrader: (45)

pull the vaccuum line off the fuel pressure regulator and see if theres fuel in it..if so thats the prob..

dirtdiggler02

iTrader: (7)

Thanks ls1 for the info. The truck only has 11,000 miles. It's still like new. I just changes the plugs recently,but i used ngk's. The intake is a mac cai with a new k&n that came oiled from the factory. I never adjusted the speedo because it is only off by a little(5 mph @55 mph). I work close to my house so i don't drive much at all. I can't really think of anything else other than a real tune might be what i need for better mileage.

Zick

iTrader: (18)

Well going to a larger overall size tire/rim is going to cause your speedo to read slower than your actually going, which in turn causes the odometer to counts less miles than your actually putting on.
If you have the onboard fuel gauge that tells you the average MPG, that will also be lower now because of this.

What size tire/rim did you have originally?

Also that large of a rim I'm sure is much heavier than the stockers were. When I had my 99' I lost about 2mpg just by going from a 265 tire to a 285. Mostly because the tire was a E load rating and the dam tire along weighed more than my stock tire/rim together.

02sierraz71_5.3

iTrader: (2)

I really dont see the MPG getting worse, I have a heavier truck with 3kstall and 222 cam I get about 9 city with the AC on and a shitty 16mpg at 80 mph with the AC on 4 people and the bed loaded full. That AC takes away around 3mpg. Plus with the heat it will cause your trims to go positive and add alot of fuel even though you dont need it. Have your tuner set the intake charge temp bias to 1 across the board thats a big reason why the people get worse mileage in the summer aside from the AC