My gas mileage on my 94 850 n/a 5 speed has been terrible for the last 6 months. I live in Chicago and sit in traffic most of the time. Last year I was getting around 320 miles per tank. Now I'm only getting around 275 miles per tank. I don't have any codes, everything is flashing 1-1-1 so my hunch is that it is the airbox thermostat. I noticed that the turbo versions do not have the intake hose from the exhaust into the airbox. What would happen if I swap out my n/a box for a turbo version? Would that help? Any thought or suggestions would be appreciated.

Your computer still needs to know what the air temperature is to regulate the fuel/air mixture.

If you think that the warm air flap in the airbox died, force the flap closed. You and everybody else do not need heated air coming into the engine.

Swapping air boxes from a turbo is not reccomended and a waste of money/effort.

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My name is Klaus and I am a V♂lv♂holic

Klaus,

Where is the sensor in the airbox that lets the computer know the temp so it can manage the fuel/air mixture? On my airbox I have 2 vacuum tubes coming out of it, but have no idea what their function is.

Eddie G

The thermostat is not electric or vacuum, it is mechanical. You will find it under the air filter and it controls a flapper to open/close cold or hot air.

You can remove the thermosat, modify it so the flapper always covers the warm air, or replace it.
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My name is Klaus and I am a V♂lv♂holic

If that's the case, then what sensor tells the engine the proper air/fuel ratio?

The MAF or AMM at the top of the air box. Along with the barometric pressure gauge, O2 sensors, and a few others.

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My name is Klaus and I am a V♂lv♂holic

Thanks Klaus!!!!!

The "winter blend" gas will cost you a couple mpg and that along with the cold weather could account for your drop in mileage. Maybe wait a while before doing anything. It may come back up when it warms up.