maybe its a gas gauge problem?

 

who did the work my brother had some work done by a major box store had some problems and took it a local mechanic and found out they didn't do half of what they where supposed to be doing and left some stuff off

 

my old 88 4x4 gets just shy of 20 MPG about 80% highway

Pull a plug out to see if they really were replaced....check the dist cap and rotor see if they look new...the things he did would be easy to see and check.

Other then that I dont know what to tell you...replaceing that stuff normally helps with your MPG *shurg*

 

I have a 2004 2dr and I am having the same problem. I got a gm 100,000 mile tune up at my local Chevy dealership that I trust and it was in the shop for a whole day. $600 later I'm getting 11 mpg. I cant seem to figure out whats wrong with it. The dealership said that they did everything right. Any suggestions?

 

what was your mpg before you went in for the tune up?

 

around 16 driving around town and about 19 on the highway. Now its 11 city and 15 highway.

 

how long ago was the tune up done? have you gone back to the dealer and explain your situation and make them check everything over again? if your mileage dropped that much something somewhere isnt right.

 

I got the tune up done in November. Yes, I've went to the dealership many of times and a personal friend of mine worked on the blazer. But the next day after picking it up i did have to turn around and bring it back because the engine light went on. They said it was just an error and they cleared it.

 

have you read post #6 on the previous pages? if not read it and check those same things out and report back with your findings, also the code coming on because of an "error" seems a lil fishy did you ask what could cause the engine light to come on for no reason and if you did infact throw a code did they tell you what the code was?