vrg3

Almost all oxygen sensors have M18x1.5 threads. So do 18mm spark plugs, actually. You can get 18mm "spark plug non-foulers" from the auto parts store that can be easily made into weld-on-able oxygen sensor bungs with a little cutting. They're basically little spark plug extension dealies: http://www.partsamerica.com/ProductDetail.aspx?mfrcode=RNB&mfrpartnumber=42009

News from Sanjay: Setright, your guess about the rad cap was correct. The gasket was badly worn; there was a groove right where the filler neck pressed against it. A new cap resolved the problem. Thanks to everyone for the help.

Even if those tests check out, you still might try subyluvr2212's suggestion. In my experience, the idle switch code is sometimes thrown when there's an inappropriate load on the TPS power supply, and that can be caused by something weird in the TPS.

Yeah, copper's a better conductor than platinum, but platinum lasts a lot longer. In my opinion, the extended service interval of platinum plugs is not really an advantage, since I think you should be removing your plugs more often than that just to check them and to make sure they don't fuse to the heads.

Yup. The heater control moves a flap that controls how much air bypasses the heater core.

Don't believe so. It's used just to gauge catalytic converter efficiency. You might need to start checking out the EGR system and stuff like that... But maybe first you should have the codes cleared just to make sure it's not actually already solved.

It may or may not clear the codes... I'm not sure. But I wouldn't think a fuel trim malfunction code could appear after only 10 miles. Maybe, though. D'oh. It could still be the ECU but I still doubt it... :|

Even if the problem's solved, it could take a few trips before the ECU turns the CEL off. Or did you have the CEL cleared after cleaning the MAF sensor and rewiring the oxygen sensor?

Excellent! That's a nice price for an OEM-replacement sensor. Certainly beats trying to connect to those weird stainless alloy wires on the stock sensor.

Draw-Tite hitch part number 36234 is specified for all 1990 to 1999 Legacies, both sedans and wagons. The wagon drawbar is different from the sedan one. It's pretty easy to install, and I'd presume easy to remove. It bolts right in after you drill one 1/2" hole in each frame rail. I towed a trailer that weighed probably around 1500 lbs on a 350-mile trip with my Legacy... My Legacy's got everything wrong with it for towing: it's a 5-speed (with a dying clutch no less), a sedan, and a turbo. I guess if it were FWD instead of AWD it would have been a little worse. I certainly felt like I was being hard on the car, but it took it like a champ. Based on that experience, I wouldn't be too worried about hauling a snowmobile trailer around with your wagon. Just drive carefully. Be very gentle on the clutch, make extra sure to leave enough room around you to maneuver in an emergency, stuff like that. And definitely practice without the sled first.

Are you pretty sure about that, coloradosubarules? I remember going to a u-pull-it and using their interchange lookup for a 91 Legacy power steering pump and being told I could go up to 1996.

Good luck!

This seems like a smart way to do it, Setright. Interestingly, on turbo models the fill point for the system is the highest point in the system -- a filler tank mounted to the intake manifold. It actually ends up filling the whole system through the water pump and through the passenger side cylinder head (through the turbo). The radiator gets filled through the engine. And when I fill my Legacy Turbo motor with coolant, unless I rush the job, I usually have very little burping to do.

Apparently the "Parts America" stores (AutoZone, Checkers, Kragen, Shuck's, etc) can special-order any Redline product. I'm sure their prices won't be as low as some of these other places, but you wouldn't have to pay for shipping so it might even out. I think Redline 75W90NS is the right stuff for both your transmission and your rear differential. Redline 75W90 is for a different type of differential.

Every time the computer turns on the Check Engine light, it also stores a trouble code in memory that explains why it turned the light on. You should try to get someone to read the code for you; it's a lot more effective than trying to guess at the cause (though the two guesses people in this thread have made are good ones). LIke WANTONSOUPGUY says, a lot of auto parts stores read codes for free as a courtesy. If it's not a big deal you might choose to leave it, but there are two reasons you probably should fix it: 1) In most states having that light on and/or having the trouble code stored will cause the car to fail an emissions inspection, and 2) If your engine develops a more serious fault you won't necessarily know about it.