Moved from va. altitude of 900 ft. to colorado. getting poor gas milage. does the dealer have to adjust anything to improve gas milage

to get an an out of paramaters setting for the air fuel mixture in the ECM I would consider a change in altitude of around 3000 feet would be necessary before the ECM would need re- programming
I would suggest that you run the fault codes as the MAP/BARO sensors may be faulty
also if the driving conditions have change ( flat to hilly) will account for lower fuel economy

I would guess your car was built to the Emission Standards
for your state,altitude etc

Still a big drop in mpg

If you ever moved, you may need your computer software
reflashed for lower elevation

I would guess the MAF Sensor was out of it's range

Check to see if any codes were stored
Need professional scanner

Look at freeze frame data unless you have been back for weeks

s-10 blazer getting very poor gas mileage 14 mpg is there any way to improve this ?

crank sensor will not improve gas milage fuel filter an plugs wire an airfilter an fresh oil should get u back were u was before

So what is the mileage and what do you expect it to be? What engine do you have? Transmission? 2wd? 4wd?what do you do with the truck? do you haul anything in it? trailer? topper? any hills where you live? short trips? highway? Elevation?.

Gas milage will vary, depending on the manner in which you drive, also poor gas milage could be due to poor maintenance. Replace the PCV valve, the oxygen sensors, the fuel filter, plugs and wires, and have the injectors cleaned, switch to synthetic oil should improve the milage. .

Smaller jets in the carb, less oxygen in the air means, you got to have less fuel in the mixture otherwise wham to much nox and no pass the mans law...

I'm not sure I have a solution to this but the change in altitude should cause a change in mpg. However, the car was not put in a box and shipped there, it was driven...and should have adjusted gradually to the change. (computer should re-calibrate). The only item that may be affected would be the map sensor. Possibly, since it has always worked at one altitude, it may have worn in that area and is hanging up and unable to adjust.
If the trip was made quickly, the computer may not have re-calibrated itself yet (depending upon how long it's been in Alaska) You may want to try disconnecting the battery and then re-connecting it, or it may need to be manually re-calibrated using a scan tool. The computer likely is working properly though otherwise with that kind of mpg you should be blowing a bit of black smoke out the back. Only other thing I can think of is to check the air filter to make sure it's clean and not restricted.
as far as the brake thing goes, after that, I would shy away from the dealer unless it's for free warranty work...I could replace the entire system three times for that price (gold plated parts?)
Well, like I said, not a solution, but my thinking on paper!!
Good luck!!!

I have the same issue of low gas mileage. My 2008 Kia Rondo with V6 (2.7Lt) gets 20-21 mpg in average. Even for highway mileage, it is around 21-22mpg. Very poor gas mileage. Disappointed. I hope it would improve in the future.

Yes, Colorado is much higher in altitude. Do to higher altitude the barometric pressure is less than sea level by a long shot. Lower barometric pressure mean that less air is entering your engine. Which in turns mean that your engine is now running richer than it was at a a lower altitude. So I recommend checking you engine timing, and adjusting your carbs air/fuel mixture. yes this means that you may need to rejet. but first there is a screw on your 22r's carb that you must adjust to lean the air mixture just right. I have had a stock 22r carbortor before and never had to rejet it. i probibly should have but it ran fine at sea level and all the way to about 10000 ft. after 10000 feet i had to lean the fuel mixture to even alow the engine to run. This screw that you must turn is hidden due to toyota not wanting you to tamper with it and burn your engine to the ground by running your engine to lean. it has a metal plug on the passenger side of the carb about the size of a pencil eraser. you must drill that out and then you can adjust the air fuel mixture. Clock wise is to lean the air fuel. and Counter clock wise is to richen the air fuel mixture.A good rule of thumb is to turn the air/fuel screw all the way clock wise and then back out about 2 and 1/2 turns. That is the factory adjustment. you may only need 2 turns out. Best of luck i hope you get it running perfect. Try this adjustment first then if it still runs rich then think about rejetting.

Here is a picture of what i am talking about.

#1 is the air/fuel mixture, #2 and #3 are cold and warm idle screws.
#4 is a A/c idle adjustment.