mmcpeck

I apologize in advance, but not sure which way this O2 sensor gasket goes.

Does the side with the metal around the edges go down against the exhaust pipe, or against the O2 sensor flange? One side has metal around the edges and one side has none. See below.

Thanks.

tj884Rdlx

doood! that's a critical question, not stupid!

you must put it so that the 02 sensor goes in the CENTER HOLE.

i'd put it metal to exhaust side, since that's the heat source. but that gasket is not uni-directional. the metal edge only maintains the integrity of the gasket so it doesn't get blown out in little bits over time. the real gasket is the center ring.

mmcpeck

Not sure where this went.

mmcpeck

Oh I see it now, it was moved to the Newbie section.

Ok so it really doesn't matter then which side faces which way, but maybe a good idea to put the metal side against the pipe?

4x4climber

As far as I know the "proper" way to do it metal side down...

mmcpeck

The hardware that held the old O2 sensor on is rusted beyond recognition, so I went and got new nuts and some washers. Can't tell if the old hardware included washers or not, lock washers or anything.

Will using just nuts be fine on it, or is it a good idea to throw a washer or lock washer on?

Thanks.

tj884Rdlx

i would definitely want to lock it down, otherwise you risk an exhaust leak. get new lock nuts and use anti-seize. you may need to replace that sensor again someday. torque to spec.

4x4climber

antiseize and lock nuts... good stuff for exhaust

mmcpeck

Would I be able to grab locknuts at any auto parts store?

4Crawler

iTrader: (3)

Auto parts store may have them, but you need the kind without the nylon insert (nylock nuts), as the nylon will melt on the hot exhaust. Or I usually use some stainless steel bolts, nuts and lock washers on my exhaust parts. And a liberal coat of anti-sieze on the threads.

mmcpeck

Thanks 4Crawler. I bought stainless nuts and lock washers for the studs that come on the exhaust pipe for the O2 sensor. Was gonna try and get lock nuts but just picked up the regular nuts and lock washers instead, will they work just as good?

I'll get some anti-sieze on there before I put it all together.

4Crawler

iTrader: (3)

Regular nuts are probably fine, they are stronger and less likely to strip than s/s. But you might find that you need to replace them the next time you change the sensor, not that big a deal.

mmcpeck

Went to put the O2 sensor in yesterday and tightened the nuts down slightly over the studs, went to torque them, one torqued down to 14 ft lbs nicely, the other just kept turning and stripped all the threads off the studs.

Piece of crap exhaust pipe. This is the second one I have brought back, the first one wasn't machined right and the O2 sensor wouldn't fit in the hole, now this one has crap studs on it and they strip right out.

Now I have to wait until Tuesday for the other one to come in, so 3 more days my truck is undriveable. Sometimes it's way more trouble than it's worth to try and do repairs yourself.

Think I'll need a new O2 sensor gasket now, since the one I have wasn't tightened down? Can I re-use it?