Hello all, new to the forum but I'm sure I'll be on here quite a bit for advice. I'm a fairly new Disco2 owner( since February). It's an 03, 150,xxx miles. I bought it knowing that it needed some odds and ends stuff done, and that it had a misfire in the engine, but it looked really cool and it was solid, no rust, and they are well known for their off-road capabilities. I got it home and plugged in the scanner and lo and behold, 8 to 10 different codes. I'm currently working on the 02 sensor, bank 2 sensor 1, should be the right side front as I read in a past thread, but my main question at the moment is how in the hell do you get that sensor out if it's stuck in the bung!? I've now broken a ratchet AND an extension. Yes I was going the right way, but the thing is stuck. I've doused it in WD-30 but even that isn't seeming to help. Anyone here have any techniques that may help me out?

 

You need to heat up the pipe and O2 fitting with a propane torch, or map gas(hotter), or a welding torch(hottest and ideal).
Heat will expand the metal and help free things up.

 

I'm not sure why I didn't think that, awesome, I'm gonna try that

 

Could you not just run the engine until it gets hot? Being careful of course.

 

Sometimes that works, sometimes it doesn't.

 

I will say that I started reefing on it while the engine was hot, probably only ran for about 30 minutes, but I think hot enough, my arms could testify to that haha

 

Well, I tried it all, heat, WD-40, pure muscle. Note a single bit of moment. Until it started to round off in the tool I bought to get those sensors out. So now its rounded off, and STILL in there. Any suggestions?

 

I had to drop the Y-pipe to get mine out. Then I used a sawzall to cut it flush to the point that I could get a 6pt 22mm impact socket on it. A couple short bursts of the impact gun spun it out, luckily without damaging the threads. I did purchase a thread chaser after the fact though should I ever have to go through that again. Despite not being a favored approach, I think dropping the pipe is a relatively quick fix for this situation. It assumes that you can get the bolts for the front crossbrace off without rounding or snapping them as well but once you've cleared that hurdle, dropping the pipe took about 10 minutes. Somehow, having unfettered access to all four sensors was such a relief that I would do it the same way next time.

 

This^
I had to have the Y pipe out, and cut 2 of them down to the hex too. I hooked 2 combination wrenches together(open and box end), heated with propane, and had enough leverage to break them loose.
I put a Small amount of anti-sieze on the new O2's threads, being very careful Not to get any on the sensor itseld.

 

God that sounds like a huge pain in the ***, but it's looking like that is probably the way I'll have to go. Damn. I checked the new o2 sensor and it already has some anti seize on the threads, thank God. So with the issues I'm having with it, when I take the Y pipe down, should I also replace the Cats too? I had quite a few misfire codes, plus the O2 sensor too, and I'm pretty sure the previous owner ran it like that, and I know that doing that will damage the Cats eventually.