sometimes no power? need help asap!!!!

[splodo49]

I just drove 2400 miles from florida to utah and about half way i started losing power.The check engine light would come on every once and a while but no difference in power or any thing when it would come on and or go off.At first i thought my tranny was going out (slipping).I didnt happen all the time just every once and while.What i realized was when it wasnt running up to par it would be hard just to keep the truck at a constant speed once i would get up to like 65 the engine wouldnt hold it their.I would have to push harder on the gas and kick it out of over drive to get the speed back up and then it would hold it only sometimes.Sometimes when i would push on the gas to get the speed back up it would feel like no power just high rpms until it hit like 3500 rpms then it you could feel the power.I dont know if its a timing thing or maybee the altitude change.but i really need help i still have 900 more miles to go and i want to be able to make threw and over these mountains.thanks much.( the best gas mileage was 200 miles to a tank thats the same mileage i was getting with my big tires also ???)i was running 31"s. for the trip.

 

[mrboyle]

First thing I'd do is get the codes read. If there is a sensor going (ie. O2 sensor, MAF, etc....) the engine will not opperate properly. Due to the altitude changes you are experiencing it is not uncommon for a sensor failure to show up. One of the sensors could have been borderline for a while, but would work within its parameters at a constant altitude. The problem doesn't show up until the vehicle is opperated at a different altitude and the sensor can't opperate in the parameters needed.

 

[MrShorty]

You can read codes yourself with nothing more than a paper clip: www.dalidesign.com/hbook/eectest.html