replacing o2 sensor

[g0tEclipseD]

im having a problem taking off my lower heatsheild so i can get my o2 sensor out. theres a nut right behind the dipstick, one beneath that one and one underneath the heat sheild. they wont budge at all. i tried soaking them in wd40 but all it did was scare the shit out of me the next day when i went out in the car to get gas. full of smoke and smelt like ass.

what can i do to get these bolts out.

 

[AWDPetmitsu]

Try using PB Blaster instead of WD-40. Let it soak in overnight and try it again. You can also run the engine to heat it up before trying to get them off but keep an eye out for any of the penetrant catching on fire.

 

[psychlow]

That same bolt is being a pain in the ass on my 92. I PB blasted the shit out of that sucker, and I still can't get it off. I think I may have to try the 'warm it up with the engine' trick.

Oh yeah, make sure you disconnect your battery before you go sticking wrenches in near that alternator.

 

[AWDPetmitsu]

Listen to that guy ^^^^^. Take the advice about the battery.

 

[DSMRevolution]

Yeah start the engine and let it run for awhile first. They should come right out no problem. Don't forget when you put the oxygen sensor and those bolts back in to use a lot of anti-seize! I figured out after a few times that it really IS your friend no matter how nasty it looks . How do you know your oxygen sensor is bad? Did you propane test it? Resistance test it? If you threw a CEL light sometimes you can get away with cleaning them using the propane torch. Just make sure that it changes voltage from .1V to.9V as it should (and falls down when you pull it out of the flame fast). Well I am sure you know what to do anyways! Good luck!

 

[g0tEclipseD]

Thanks for the info. I thought all the wd40 was gone late the next day but when i opened the hood it was full of smoke atleast nothing caught on fire and its fine now.

I tried heating up the engine before trying and still didnt work.

Ill have to try PB Blaster

I got the car recently and found out it has the original o2 sensor. That would explain >15MPG / >180miles/tank that im getting right now while stock completely stock and mild boosting.

my o2 sensor came with a bit of anti-seize. what does it do?

 

[DSMRevolution]

Originally posted by g0tEclipseD
Thanks for the info. I thought all the wd40 was gone late the next day but when i opened the hood it was full of smoke atleast nothing caught on fire and its fine now.

I tried heating up the engine before trying and still didnt work.

Ill have to try PB Blaster

I got the car recently and found out it has the original o2 sensor. That would explain >15MPG / >180miles/tank that im getting right now while stock completely stock and mild boosting.

my o2 sensor came with a bit of anti-seize. what does it do?

The anti-seize is what goes on the threads of the o2 sensor. Make sure to use that as it keeps the threads from seizing so it comes out easier next time. Prevents basicly welding itself to the o2 housing. I have seen some stuck in there pretty good. Also low MPG doesn't always mean a bad oxygen sensor. Good luck!

 

[g0tEclipseD]

What else could be the cause of my bad milage?

 

[the_jester]

im getting 12 MPG and im about to change my o2 sensor too, but they cost 140$ is that normal and the one guy said bad mileage isnt always because of the o2 sensor so what else could it be?

 

[doodie]

look for a 2-3foot pipe. Slide the pipe over into the handle of your socket wrench and tear away. The bolt should slide right off. My o2 sensor was pretty much siezed into the o2 housing. I broke 2 socket wrenchs before I bought a expensive one and finished the job with the breaker bar.