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Showing results for tags 'bad mpg'.
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Having a major loss of power especially noticable when going up hill, and terrible fuel mileage(350 km to an 90 litre tank) have done all the basic things it could be like maf sensor, plugs + wires, Fuel filter, and air filter. I’ve heard talk about it being the cats but they are relatively new and got no codes, and help would be very appreciated!
I have a 2001 GMC Sierra with the 5.3 Vortec with about 211K miles. Over the past 5 months or so I've noticed the MPGs have TANKED. Be aware this is a Regular Cab 2WD! Early spring last year I was getting about 15-16 MPG with 75% hilly-city driving. Summer came around, I was still receiving 15-16 MPG. As of today, on my last fill-up I averaged 13.4 MPG. Previous two fill-ups were in the ~14.5 range. I very rarely pass the 2000RPM rev-range. I have a code that pops up every once in a while for a Downstream O2 sensor. I have a pending code for a UPstream O2 sensor. I've heard the Upstream sensors have a large play on MPG? Trucks rear end fluid, engine oil, and transmission fluid were changed May 2018. I also cleaned my Air Filter, MAF and Throttle Body about two days ago to attempt a quick fix. Any tips will help. Things I've also tried: Seafoam (2 weeks ago) runs wayyy better Marvel's mystery oil (mid-summer) did not change at thing...
Hey guys, first post on here and I've got something that stumped me 100%. I have a 2005 silverado 1500 flex vin code Z. It Idles rough it has terrible acceleration, wide open throttle it takes off like nothing is wrong. It misses on 7 every time, misses on 2 every other time, every other cylinder misses here and there. No misses when in park and rpms are kept about 2500. CEL flashes most the time when accelerating (except WOT) otherwise the light is on solid. It has 220k on it and I have replaced alot of parts. New parts All 4 02 sensors OEM Plugs OEM wires OEM Fuel pump OEM Throttle body cleaned 3 stage fuel system cleaner BG Brand Air filter believe it or not OEM again New transfer case (unrelated issue) I have covers the base of the intake with brake cleaner multiple time, no signs of leaks. I've had the smoke machine hooked up 3 to 5 times and again no signs of leaks. At this point what is the best route to take? Remove intake manifold so it's easier to get to and replace the main grounds behind the heads and replace gasket at the same time? Replace the pcm? Replace throttle body maybe? Any other suggestions or recommendations would be greatly appreciated.
Hello, I have a 2000 Silverado 1500, 3.73's, 285/75/16 AT's, K&N intake & duel Flowmasters exh. The truck has a 4" Rancho susp lift that sits at about 2.5", and has rear leaf's from a 2500. Currently apprx 118k miles on it. I love the truck and trust it enough to go anywhere in it. When I 1st bought the truck I was getting around19-20hwy. Lifting it cost me 1-2mpg's, so I was getting 17-18hwy. At about 50k the MPG's dropped dramatically. I started getting at best 15mpg no matter how easy I took it. I had everything I could think of looked at. I had two Carbon flushes done to it by the dealer, changed plugs, Flitters, tranny serviced, rake added to the front, pumped tires to max. I've really tried everything I could think of. No one has been able to give me any direction on how to recover any mpg's. I use the truck for work daily, I do a lot of driving, and as of the last 30k miles I've been getting no better than 12mpg's on my mixed use tanks. On the tank I'm on currently, its looking like I'm heading for about 10mpg's, And I've had enough!!! I love the truck but there is no reason a light use of a 1/2 ton should be getting big block type mpg's. Can anyone please help!!!!? I was told of a kit called something like a spyder injector kit, that swaps out the injectors. When I search I find stuff for the old 5.7's and 4.3's but nothing on the 5.3L. I don't expect to get great Mpg's out of a truck driven in around the city, but 10-12 is rediculous! I don't want to sell the truck but .55/mile doesn't ease the pain of 10mpg's. I mean if that's all the better I'm gonna expect I should at least go get a 2500 or 3500 with a big block, cause then I can actually work the truck. Please Please Help! Thank You