What size is that? None of my wrenches seem to fit around it and I can't get it off with a pair of plyers... is that gonna be rusted in as well? It just unscrews correct? I'm having all sorts of fun with this midpipe let me tell ya!! Any suggestions are appreciated... I'd love to get this midpipe in at some time!

 

i used a crescent wrench to get mine off. spraid them with wd40 let it sit 10 mins took them right out.

was easy install for me.

 

same here. Mine came out really easy, but I only had 6000 miles on the car.

 

There's a special wrench for O2 sensors.To get a stubborn one off,try heating the area around the sensor with a torch.Don't get it red hot but just hot enough,then squirt some penetrating oil around the sensor.This might catch fire!!!When the fire goes out use the special wrench or socket with a breaker bar if needed and turn it out.It might pay off to just get new ones and be done with it.

 

Try letting it cool and spray wd-40 on it. it will come off easier. I jsut got done reinstalling my x-pipe last night and had hard time with the header bolts.
Sprayed wd-40 on it came right off. if that doesn't work you might have to get a new o2 sensor. good luck

 

They also make special deep well sockets for taking off 02 sensors. Maybe you should invest in some if you ever need to take the new pipe off and put the stock one back on.