Quick question: does unplugging the battery reset anything that the dealer must fix?

[SubaruMN]

If I unplug the ground to work on the car, will anything need to be reset like a radio code or the remote unlock/lock? Thanks.

[jp1203]

Originally Posted by SubaruMN

If I unplug the ground to work on the car, will anything need to be reset like a radio code or the remote unlock/lock? Thanks.

Nope.

The radio, trip odometer, and computer will reset but that won't affect keyless entry or anything.

Also, in most states with emissions testing it won't pass until the computer reports everything as "ready," but it should do that within 100 miles or so.

[SubaruMN]

Thanks for the quick reply. I may now proceed.

[ETC]

There isn't anything on my car that I'll ever allow a dealer to "fix" ;]

If something goes wonky on you, let us know, we've probably done the same thing and figured it out.

[SubaruMN]

Yeah you guys are the best. Saved me a ton of money and taught me a lot about Subaru maintenance.

Presently I'm trying to change my front/upstream oxygen sensor and can't get the bolt holding the sensor in place out for the life of me. It just won't break loose. Currently soaking it overnight in a bath of PB Blaster.... If it doesn't work tomorrow then I think I'll be forced to take it in.

[ETC]

If it's badly rusted, use a relatively fine wire brush to clean up the spot where the sensor meets the bung [yeah I know, but that's what it's called ;]. Soak with PB

What Are you using, a O2 sensor socket ? or a closed wrench ?

I've had good luck with rusted ones by giving the wrench a good smack with a deadblow hammer ... breaks the initial rust bond and, that's what's giving you trouble. The issue most of the time is getting a good swing at the wrench.

[ron917]

Warming it up a bit can help free a stuck O2 sensor. Run the engine for a minute and try again. Be careful, things can get hot enough to burn you.

[SubaruMN]

Got it to break free! Thanks for all the help. That was very tough. I think soaking it overnight in PB Blaster did the trick. That stuff is amazing. It is complicated by the the very tight quarters. If I could just walk up and stick my breaker bar on there it would be a piece of cake. But it is VERY tight. I was actually about to give up and then tried my little socket wrench and it worked. Couldn't believe it. I think I just didn't have a good angle with the breaker bar. Now I just worry I horsed the new one down too tight. I tightened it with the socket wrench and then tried my torque wrench and believe it or not was able to get it in there, and it was already at 15 ft-lbs (which I read was the right torque). I did not play with fire and try to loosen it and retighten with the torque wrench. I also put a lot of Loctite anti-seize on there. A little came on it but I coated it.

Now, returning to the original topic, as soon as I turned the car back on (battery unplugged for 36 hours or so) the check engine light stayed on. I thought the computer would have reset. Does this mean that it or something else is already broken? I'm going to swing by Advance Auto and wipe the computer and see what it reads tomorrow.