Replacing O2 Sensor
 

Hi!

I have a Honda Civic 2000 DX.
I'm trying to replace my O2 Sensor but first, I need to remove two bolts from the heat shield. Anyboyd knows what wrench size I need to remove them? I can't find the right size.

Thanks,
Engineer

Re: Replacing O2 Sensor
 

Just did this last week, although mine is a 98. Pretty sure it was a 12mm.

Re: Replacing O2 Sensor
 

Thank you! Any recommendation to loose a stuck bolt?

Re: Replacing O2 Sensor
 

Use liquid wrench or something like that. Do you really have to remove the heat sheild? They sell O2 sensor removers so u can do it easier without removing the heat sheild. BTW just so you know the bolts ARE going to snap if your talking about the catalyctic converter heatsheild. Mine did.

Re: Replacing O2 Sensor
 

yeah just get an o2 sensor socket with a cut in the side for wires to fit thro.

Re: Replacing O2 Sensor
 

For the bolts on cats and headers, it will be very hard to remove them. Especially from the cat back. They rust over the years and the only way to remove them without breaking them or cutting the pipes is by taking it you a muffler shop and having them torch the bolts and them impact them off. If you have the equipment yourself you can do it too. The o2 sensor bolt may be rusted on there well but I don't recommend torching the sensor... You can try some type of rust lube otherwise try the socket gearbox is talking about.

Re: Replacing O2 Sensor
 

If the sensor is bad does it really matter? They usually come off easy since they were greased from the factory. The sheild bolts however will probably still break even if you torch them because they are so weak and small.

Re: Replacing O2 Sensor
 

Hi Guys... I need to replace the front sensor (I got a code P0135) .. so, do you think that I don't need to remove the heat shield? I have a o2 sensor wrench.

Thanks for your recommendations.

Engineer30

Re: Replacing O2 Sensor
 

As said before you do not need to remove the heat sheild. Simply use the tool, the tool is able to get in there even though the O2 sensor is recessed. I remember doing it on my car. It was really easy. I broke one of the heat sheild bolts on my car before I decided I needed the O2 sensor tool. Its super ****ing annoying, now when I idle its so loud from the vibrations in the heat sheild. I reccomend you dont mess with the heat sheild unless you have new bolts or want to remove it completely.

Re: Replacing O2 Sensor
 

Like I said, I just did this last weekend on my 98 DX. I absolutely HAD to remove the heat shield, no way I would have gotten the O2 sensor tool around the sensor without removing the shield. I did borrow the correct tool, with the slot for the wires, from a local auto store. Even then, there was a minimum amount of 'turn space' available.

My heat shield bolts came out relatively easily, but my o2 sensor was a total bitch. I warmed the engine for a few minutes, soaked the sensor in WD40 (all I had), tapped it with a hammer a dozen or so times, and cranked the hell out of it until it broke free. The limited space is what made it the most difficult. By the way, I'm a weightlifter/bodybuilder, and by no means have a 'girls grip'....sometimes a 500 lb deadlift comes in handy outside of the gym...lol.

Re: Replacing O2 Sensor
 

01-05 civic is easy with just the o2 socket. and you prolly need to jack up the front to get under there. shouldve used a breaker bar or cheater pipe on the end of the socket. i broke mine free in two tries and i have girly arms. you dont need muscle if you use a long enough pipe.

Re: Replacing O2 Sensor
 

Didn't have a breaker bar, just my standard 8 inch socket wrench. Breaker bar is on the list of 'to buy' items. And you're absolutely right, I'd take brains, and the correct tools, over brawn any day. But eh, we work with what we have..lol!

Re: Replacing O2 Sensor
 

just get a $2 exhaust pipe to put on the ratchet.