My 1500 has gone from about 15 city and 20 Hwy to about 7-10city and 15-17 hwy. I have also noticedthat when the engine is under load (pulling a small trailer or going from adead stop up a medium grade) it is very sluggish to respond. The system is not throwing a code. I took it to the dealership and could notfind anything…they did clean the Throttle Rod (which actually helped a little.) Now when you start it from a cold startit runs rough for a minute or two then smooths out. I took it back to them, and they say they sayit is working "to spec.”

I have changed the air filter and run fuel injector cleanerthrough it.

Can anyone give me some ideas as to what is wrong?

 

Unfortunately, there are a number of things that can cause a sudden change in fuel economy. Normally the first place to look is was there any service performed on the vehicle just prior to the change in fuel economy? Aside from this the next items to look at are:

- fuel leak

- low tire pressure
- dragging brakes
- blocked air filter housing. (I know that you mentioned that you changed the filter, but this time of year, the animals are starting to get ready for winter and you can find all sorts of things in the strangest places)
- dragging A/C compressor / idler pulleys / power steering pump etc

Since the vehicle was in the dealer, I assume that you do not have any stored error codes.

 

Thanks, No I did not have any stored error codes. That is one of the issues it seems that is all they want to do is check for the codes and drive it a short distance.