Tips on removing seized downstream o2 sensor?

Hey guys. As the title states I am wondering if anyone has any tips for removing the downstream o2 sensor. I went to tackle this a bit ago but for the life of me couldn't get the sensor out of the cat pipe. Anyone have any tips on doing this? Is PB blaster or WD-40 safe to use in this area? I didn't want to soak it unless it would be ok to do so.

Use PB Blaster but only spray the threads where the sensor screws into the pipe. I'd hit it several times on different days. If you are using a special socket try the "offset" or shorter version sold at Harbor Freight. The long version has a gap in the socket wall which is too wide and will flex.

I am already using a shorter offset socket that I bought from a local auto parts store. But I think that PB blaster or something similar will be necessary to work this thing out. I will have to soak it a couple times later on and attempt to tackle it again.

Use a torch only way I got both of mine out.

 

 

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Use a torch only way I got both of mine out.

 

 

Sent from my iPhone using Tapatalk

 

How easy would it be to mess up the o2 bung by using a torch?

If I remember correctly, I had already removed the downpipe and was able to slide the box end of a wrench over the plug and around the sensor and smack it until it came out. I don't have fancy o2 sensor plugs but it worked.

Just to rub it in a bit after my effort last weekend. Gave mine a blast with wd40 about 10 mins before taking to it with a fixed head crescent. Came loose with almost zero real effort.

The joys of living in a part of the world where the temps relatively warm and roads don't get salted

Just to rub it in a bit after my effort last weekend. Gave mine a blast with wd40 about 10 mins before taking to it with a fixed head crescent. Came loose with almost zero real effort.

The joys of living in a part of the world where the temps relatively warm and roads don't get salted

 

I hate you....our winters can be quite nasty here and even if they aren't too bad the roads are salted quite heavily. So this car has seen it's fair share of wet and salted roads. Which is of course why removing any bolt from the underside of the car is such a pain in the ass...

Assuming you are replacing the sensor:

1. Unplug from harness, and remove exhaust section

2. Cut / Break off wiring and ceramic section

3. Heat with MAPP torch, remove with impact / breaker

 

You can also try heating it and applying paraffin wax to the threads while hot.

Assuming you are replacing the sensor:

1. Unplug from harness, and remove exhaust section

2. Cut / Break off wiring and ceramic section

3. Heat with MAPP torch, remove with impact / breaker

 

You can also try heating it and applying paraffin wax to the threads while hot.

 

I may have to resort to removing the exhaust section to get this thing out. I was hoping to avoid that unless I was replacing the cat pipe altogether (which still might be necessary if this sensor doesn't fix my CEL).

 

Can I torch it with the pipe still installed?

Did you try a penetrating oil? WD40, PBlaster, Kroil? You're replacing a sensor, you can't screw it up any more than it already would be.

 

Have you tried using a cheater or breaker bar?

$0.30 resistor at Radioshack

Did you try a penetrating oil? WD40, PBlaster, Kroil? You're replacing a sensor, you can't screw it up any more than it already would be.

 

Have you tried using a cheater or breaker bar?

 

Used PB once and couldn't get it free. Soaked it a second time but due to family issues couldn't get to it. I think I will soak it again Saturday morning and tackle it shortly after. I needed to get a new adapter for my breaker bar to be used in the 3/8" sensor socket which I just picked up yesterday so I will attempt that again.

 

$0.30 resistor at Radioshack

 

Please elaborate.

I think the resistor would override the effects of replacing the catted uppipe on 2005-6 models (I don't know if the non-turbo "i" model also has sensor which you plug the resistor into). If we're talking downstream o2 sensor I'm thinking the resistor might clean up some effects of removing the uppipe catalyst, but I wonder if you'd want to shut out all information your car is running dirty (from other causes).

Well the 2.5i doesn't have an uppipe. We only have a cat pipe with two catalytic converters. So I don't know if the resistor would work for this application. Mostly cause I don't know how the resistor works in general.

 

It is the downstream o2 sensor that I am attempting to replace to get rid of my CEL. What do you mean by shut out? Are you referring to a tune? Or just have the codes wiped for the time being? I would rather not deal with resistor-type fixes if it's going to cause a problem with emissions. I've talked to some local subie guys and a lot with NA cars have said that they get dinged on emissions inspection if the shop notes something out of the ordinary (modified) exhaust. I was originally going to go with Tsudo UEL and a hi-flow cat but have put that on hold due to the possibility that emissions would be a headache. So I'd like to just get this sensor replaced to see if it fixes the problem.

Used PB once and couldn't get it free. Soaked it a second time but due to family issues couldn't get to it. I think I will soak it again Saturday morning and tackle it shortly after. I needed to get a new adapter for my breaker bar to be used in the 3/8" sensor socket which I just picked up yesterday so I will attempt that again.

 

 

 

Please elaborate.

 

Indeed. What is this RadioShack you speak of?

 

Fix it proper. I think the extra soak time on the PB will help it. You really need to put some muscle into it on the old rusted up ones. It will come out.

What are you going at it with currently; o2 socket, or wrench? Never took more than few shots for me using whack-a-wrench technique -- torch, PB, leverage are all great, but incorporating some kind of impact can be huge in dealing with any seizure.

 

(edit - just saw you were going with socket. wrench [+hammer] might be worth a shot, gl)

Indeed. What is this RadioShack you speak of?

 

Fix it proper. I think the extra soak time on the PB will help it. You really need to put some muscle into it on the old rusted up ones. It will come out.

 

I lol'd.

 

But seriously. I do want to do it proper and not have to work about some kind of hack job later.

 

What are you going at it with currently; o2 socket, or wrench? Never took more than few shots for me using whack-a-wrench technique -- torch, PB, leverage are all great, but incorporating some kind of impact can be huge in dealing with any seizure.

 

(edit - just saw you were going with socket. wrench [+hammer] might be worth a shot, gl)

 

I'm going to soak it Saturday morning and then probably attempt it again. Or soak it then soak it again on Sunday and attempt it then. I have a small 2 lb sledge that I will try to use with it to get the damn thing out. I was hoping to avoid using a torch but if necessary I will give it a shot.

 

I'll be sure to report back after the weekend.