O2 sensor

Hey guys,
I'm trying to replace the O2 sensor that is located towards the end of the cat. pipe. The sensor is shot so I haven't been to light on trying to get it out... Anyone have any advice??? Just shy of dropping that head pipe and really wrench on it...as a last resort
thanx

Are you referring to the 02 sensor before or after the CAT convertor?

All you need to do is spray some WD40 at the bung area where the sensor threads in, let sit awhile, warm the engine up some and then use a universal 02 sensor removal 7/8" socket which has the cutout for the 02 sensor wiring harness and a 3/8" drive ratchet or breaker bar with extension. Most auto parts stores have the socket tool for $10 or less.

Also, it would help to post your year and model Grand Prix.

yeah it's after the cat and i did purchase the socket for it... it's really siezed in there... iv'e hit it with pb blaster many times trying to loosen it

Yeah you must live up North. I used an adjustable wrench on mine. The rear 02 sensor is in a bad location. Do you still have the u-bend?

i think persistence is the best solution. i had the same trouble with my o2 sensor, i live in canada btw. Basically a alot of PB or equivalent, trying when the exhaust is really hot, and a massive wrench with a pipe on the end of it for added torque.

I did have to get under there 2 or 3 times to try, i didnt want to be beaten by a simple sensor lol.

Make sure you use PB on a hot pipe in a well ventillated area however, the fumes it gave off were pretty strong.

-Steve

If it's really stuck, cut the wires (only on the old sensor obviously) and use a standard 6-point deep-well socket for removal, as it will grip better than the slotted socket will. Then use the special socket to install the new one.