95 Accord EX auto 4cyl getting 21 mpg. :(

[Catterman]

Hey guys, my 1995 Accord 4 door, VTEC, auto, 4 banger, with 130,000 has only gotten 23 & 21 mpg the last two tankfulls. It has been colder, but I haven't let it sit and idel either, I get in, start it, and drive. Those are in town numbers too, but even still I was at 28 just a few months ago.

It had a FULL tune-up about 20,000 miles ago, including plugs, wires, fuel filter, dist cap, rotor, and air filter. I use Amsoil synthetic oil.

Any idea what it could be? Thanks so much.

[mpumas]

Check your tire pressure. When it is colder, air pressure in the tires goes down. Is there a brake dragging. Check your rims after driving to see if one is hotter then the others. You should be seeing about 26 mph.

[Catterman]

I will check that tonight, thanks. Tires look good though, but that can be deceiving. I also dumped some Sea Foam in there so we will see if that does any good.

[Catterman]

Also, my exhaust has been sounding a little louder then normal, could it be soemthing with that, or my catalytic converter???

[Igovert500]

All the above mentioned, especially tire pressure adn dragging brakes are great advice. 2 more things.

1) it's colder out (finally) adn therefore hte air is richer in oxygen. You are sucking in more oxygen in average and your ecu is seeing that and sending more fuel to compensate, which could bring down your mpg a tiny bit.

2) you said your exhaust is louder, probably an exhaust leak. Depending on the location, these can confuse your o2 sensors by eitehr creating turbulence and resulting backpressure screwing with the airflow, and also allowing exhaust gases to escape between the two (sets?) of o2 sensors...causing them to get inaccurate readings and send incorrect values to the ecu, which could cause it to run richer.

Any or all of these combined could be responsible in theory. Check your tire pressure, keep your driving habits in mind (they can have a HUGE effect), make sure your brake pads aren't dragging, and look under the car on a cold morning and see if you can see any exhaust escaping before the mufflers in the back of the car (exhaust leaks are very visible on cold mornings).

[Catterman]

Thanks, I will check the exaust this weekend, going to get cold!