Rep Power: 0

I have a MT 2000 EX with ~165k miles. Normally I average somewhere between 33-36 MPG. A couple months ago I took my car in for service and they put in a new air filter because the old one was dirty. Immediately afterwards I started to notice my fuel economy dropped significantly. Over the course of three or four tanks of gas, I was now averaging 25-27 MPG. I contacted my shop and brought the car back for them to take a look at, and they checked to see if any hoses were knocked loose or if anything else was damaged. There was nothing that they could find, so I had them do a more thorough search. The spark plugs were old but not really bad, so they replaced them. They also replaced the fuel filter and cleaned the fuel injectors. They checked the thermostat, which was fine, and the O2 sensor, which they said was "sluggish" but still working. After all that nothing has changed, and I'm still getting poor MPG.

Any thoughts?

Thanks!!!

 
Rep Power: 229

Stuck brake caliper?

maybe check to see if the shop actually changed the filter, some shops charge you and leave in the old one.

also check to see if the new airfilter has a primer filter glued on top of the standard filter, if so remove it.

 
Rep Power: 0

They definitely changed the filter, I trust them completely. Also, how would I know if there's a primer filter?

 
Rep Power: 222

Winter gas

 
Rep Power: 0

I don't think it's winter gas, I've had the car for 5 years and I've never had this issue in the winter.