POOR gas mileage, 1996 850 TURBO

[shutterbugstudio]

I was getting great mileage up till about a month ago. Go figure, gas at all time high and my car starts to suck it up. I was getting about 20-22 combined and close to 30 on the highway, then all of a sudden it is down about 25%. No error codes. I see where they talk about the airbox sensor, but when I took mine apart, I sure didn't see one. Am I looking in the wrong place or is that just on the non turbo models? I suspect the front oxygen sensor, but no code is coming up. I did find a couple of the small hoses going to the airbox were off. Would that cause it? Just really stumped. I can't imagine a tune up would give me back that much mileage. I am quite the novice when it comes to cars. If this has been covered before on the turbo models, then please just direct me to the right place. Can't seem to find anything conclusive.

Thanks everyone.

1996 850 Turbo
1994 850 Turbo
Previously:
1984 240
1987 240
1991 740
1993 740
1967 P1800
1969 P1800

[MadeInJapan]

I'm relocating your thread to the 850 section. Yes, a few hoses off could cause this...more air and it will burn rich, sucking down more gas. Also, as you suspect, it could be your front 02 sensor starting to go. Usually a sign of it going is the decreased mileage before it finally gives itself up and sets a code.

[Ozark Lee]

I see where they talk about the airbox sensor, but when I took mine apart, I sure didn't see one. Am I looking in the wrong place or is that just on the non turbo models?

The turbo models don't have an airbox thermostat.

...Lee