Hobbitos

Clarification - when I said heat car I meant start car and let it run for a few minutes or drive it around.

I would not use a torch either.

Furthermore - us that wrench with a breaker bar if possible. And make sure not to twist the cable.

lodifreefly

iTrader: (1)

after trying for like 30 minutes with penetrating oil and a socket, i finally ended up positioning myself under the car, hanging the socket from the nut (making sure it was completely seated) and giving it a solid kick. broke it loose and it came right out after that with no damage.

I wouldn't recommend doing this, since any number of things could have gone wrong (worst case, car could have come off the jack stands), but it worked for me

Hobbitos

Good Job!

evo unknown

iTrader: (25)

pb blaster several times waiting a good amount of time in between each spray. letting the car just run heats it up. but maybe a torch to heat it further.

TSiAWD666

iTrader: (5)

WD40 is a joke when it comes to loosening rust. First timers always look to it because they've heard of it their whole lives, but anyone that wrenches on a car knows it's pretty useless when it comes to loosening rusty nuts and bolts. PB Blaster is what you need.

Evo_Someday

As many have said.. PB Blaster and an 02 sensor socket is all you need. That and maybe a long handled breaker bar. But have patience and let the PB blaster soak for a while first.

srcevo8

iTrader: (10)

Good info guys.

funks

iTrader: (4)

If you are also gonna remove the downpipe, you can just unplug the sensor from it's connector (floor of the front passenger cabin) so you don't have to unscrew it while under the car.

You can then remove the o2 sensor and apply proper leverage when the downpipe is off the car. Oh yeah, might be wise apply anti-seize to the sensor's threads before putting it back and don't try to apply gorilla strength to it, torque it to specs.