MY mpg's.
 

My 03 1500 4.7L only gets 12 mpgs highway. When I am cruising at 45 - 55 mph, When I hit the accelerator, my truck will not move until I hit the accelerator enough to kick in the overdrive. So basically I can only accelerate using overdrive. What can this be? I changed the plugs and the fuel filter. Took the air box off and drove like that... nothing.. No codes come up either.

RE: MY mpg's.
 

Could be the torque converter...that would explain the bad mileage also. Check your tranny fluid and make sure it's at the proper level..

RE: MY mpg's.
 

OK, will do. I'm not that good with these things, so can you explain the function of the torque converter (in a nut shell) so I know.

RE: MY mpg's.
 

It could also be your cats. I have seen them get clogged and really takes away the power.

RE: MY mpg's.
 

thanks a lot. Would the cats being clogged throw a code?