replaced my rear o2s beginning of the summer and got two codes for the front o2s so i ordered them up, got em, got a tubing wrench and went to town, didn't get too far. So i ordered a oxygen sensor wrench and that doesn't grab a darn not to mention one of the o2s is a bit stripped, both are pretty seized in the pipe, so i can either take some penetrating oil and a pair of vice grips or take it somewhere. Any suggestions on how to gain access to them with out too too much effort? I've contemplated unbolting the cats from the headers and muffler but that would be a lot of work that i don't have time for. Excuse my poor wording, a bit flustered at the moment as most may understand

 

Penetrating oil is a good idea. They make special wrenches for these but I never needed one. Front sensors are only used for emissions, or as failovers for the rear sensors.

 

Soak them overnight in lube. Cut the wires and put a deep well 6 pt socket on em.

 

2x on that,an the thread size is 12mm x 1.25....should you need to tap the holes

 

Soak them and then heat them up, and soak them again.

If that fails, take them somewhere like a muffler shop and ask them to torch them... needed the torch for my driver's side, and the muffler shop was kind enough to do that for me for $30

 

As mentioned, penetrating oil and a deep 6 point socket. I think you want to apply the heat to the bung more than the sensor. The idea is to heat the surrounding metal enough to expand it just a hair, thereby lossening the sensor.

 

Have the tap ready cause the threads like to come off the sensor and stay in the pipe

 

Use Bostik Never Seez on the new ones so you don't need to go through the ordeal again next time.
http://www.bostik-us.com/our-brands/never-seez

 

Finally got them out. Picked up a deep socket, had some mmo deep creep from the last job(front brakes) and clipped the wires and went to town. Went very smoothly with the right tools. Maybe she won't bog so bad. I'd post pictures of the bad sensors but I have yet to learn that feature

 

Post the new O2 results if you have time.