Horrible gas milage, but engine runs perfect? No Cels!?!?!

[douglas vincent]

Getting something like 10 mpg.... When I bought it a couple thousand miles ago, we were getting up to 30 mpg on the freeway. Now it getts like 100 miles to the tank.

NO gas smell

NO Cels...

Runs and drives perfect.

?

O2 sensor?

[Splinter]

Try running with O2 disconnected and see what happens

[206er]

if it doesnt smell like its running rich... fuel leak? or did you mean you dont smell a fuel leak.

[Legacy777]

Which car is this for.....one of the wagons you recently purchased?

[wallgood358]

I am having a similar issue with my 92 Legact Sport. I get mabye 12-13 miles to the gallon in town. Just had a recent tune up and run great. I do have a small air leak in my turbo inlet duct that i know can affect performance.

[DTSJR]

My gas mileage has been horrible too. Ive had the car for almost 2 months now, and Ill be lucky to get 20mpg just driving highway. When I got the car I changed the oil, PCV valve, and the air filter looked brand new. When I noticed my mileaged sucked I checked for codes and I had one for my CTS, so I replaced it. No difference. I havent done plugs and wires yet, so thats next. I might also swap the coil pack to an Impreza one.

[dscoobydoo]

Curious which car this is on Douglas?
If it's the Red S/C car, then good luck finding it as you have gone beyond normal bounds on that one.
Currently on our 93 SS with the 16g and 3 inch exhaust 9 psi, I still consistently get 22 mpg.

[scuzzy]

Getting something like 10 mpg.... When I bought it a couple thousand miles ago, we were getting up to 30 mpg on the freeway. Now it getts like 100 miles to the tank.

NO gas smell

NO Cels...

Runs and drives perfect.

?

O2 sensor?

people stealing gas out of the tank.

if you were leaking or running rich, you'd smell it. gas is very easy to smell in very small amounts. to be missing gallon says something is happening to it.

[Bheinen74]

Please try swapping the COIL, even a used one to try out. If a coil is getting tired, the spark wont be so good, worth a try.

[sammydafish]

I say O2, maybe coolant temp sensor. O2 is probably slow. Coolant temp is easy to check with a scan tool.


does it seem low on power at all? Check cam timing, could be off a tooth causing you to loose efficiency but not enough to make it run bad.

[Brat4by4]

Check the PCV valve. Cheap and quick fix. I think this is what allowed my Sport Sedan to start getting over 300 miles per tank (when I'm nice with skinny pedal on the right).

[turboleg]

I had a problem like that on my NA. Would drive it around and get around 24 mpg. Usually get around 32-34 with it. I tried everything I could think of. Turned out to be the left rear calliper holding on to the wheel just a little bit. It would break free at higher speeds so I never really noticed it. Interestingly enough I never smelled that nasty hot break smell and could never hear any real rubbing over the sound of my snow shoes. It became obvious when I heard a grinding noise. Took off the wheel and no more break pad on one side. Apparatly the pad had finally let go. (its probably stuck in the front of a dodge ram somewhere) It was pretty obvious since I had just changed the pads on the car.

Put a new calliper, disks, and pads on and she was ready to rock out at 34 mpg again.

I still can't believe it wasn't noticalbe when I drove it....sometimes you just have to shrug your sholders.

[douglas vincent]

Still havent had a chance to work on the wagon (the purple one).

But since I posted, the damn dog ate the ENTIRE rubber window gasket on the rear passenger window. And one seat belt. Damn Doofus Dog....

[turboleg]

Jesus...

Hopefully he didn't eat the belt buckle...that could be tricky on the way out.