New exhaust headers, additional emissions monitor device ports - recommended thread sealant

[Rangergirl92]

Hello!

I bought a set of Hedman headers for my Ranger and they fit and all is kosher there - there is one additional O2 port on the driver side and another port for additional emission control monitoring devices on the passenger header pipe. My truck is older with an OBDI system so there is only one Oxygen sensor for my system that sits just upstream of the cat at the Y junction. I am looking to buy plugs to seal off those other two holes since I do not need them.

Hedman just replied "we don't sell parts to disable emission systems" (I can't even with this level of incompetence...) Like I am seriously just trying to adapt my system to its stock configuration and you do not seem to understand the basic concept that generational differences mean different configurations... smh... anyways...

So that being said, I know that the O2 sensors are M18-1.50 so I can find the plugs on like Amazon or Granger. What type of sealant do y'all recommend for an exhaust system in this context?

Thanks!

 

[sgtsandman]

I don’t know if there is a sealant that can take the temperature the headers can get too. A tapered thread (pipe thread) plug should seal it up fine.

 

[alwaysFlOoReD]

Muffler cement?

 

[Blmpkn]

Half a tube of welderup should work.

 

[Shran]

I'd probably just screw the plug in and call it good. Muffler cement might work though. You could also just get an O2 sensor, clip the wire off and screw it in to plug the hole... or just cut most of it off to make a plug... I don't think the thread is tapered there so a normal pipe plug style thing could potentially work itself loose over time.

 

[89Twincharge]

Just use a brass npt (pipe) plug the taper will seal fine then use a small punch and peen three or four dimples around where the plig threads meet the exhaust threads so it doesn't work it's self out... I've used actual O2 plugs with sealers and over time the sealers always deteriorate and the plugs works out...

 

[BiggSherm1988]

a good quality bolt that isn't too long and a bunch of anti-seize.

 

[pjtoledo]

I don’t know if there is a sealant that can take the temperature the headers can get too. A tapered thread (pipe thread) plug should seal it up fine.

O2 sensors are a straight thread, not tapered.
they are the same as a spark plug.
high temp anti seize should work.

JEGS 30748: O2 Sensor Plug 18mm x 1.5 Thread - JEGS High Performance

 

[rubydist]

The oxy sensors have a compression washer on them like many spark plugs. If you can harvest those off old oxy sensors and put them under the head of the plug/bolt you buy to fit in that hole, they will seal up just like an oxy sensor with no sealant at all.

 

[jerkyboyxiii]

Walker 35299 is exactly what youre looking for...

https://www.amazon.com/Dynomax-35299-Hardware-Hego-Plug/dp/B000A8MQM2?tag=959media-20

 

[gw33gp]

JB Weld has an inorganic adhesive/sealant that can be used on exhaust systems. They state it will take up to 1000F. That Walker plug looks good, but I think you would still need a washer seal or sealant to make is totally seal.

 

[scotts90ranger]

That Walker plug is fine, don't over think it, those plugs are slightly tapered and jam in there decent, just tighten good without sealant...

Exhaust temps can get up to 1400F, and any leak through threads isn't enough to worry about...

As for the other plug, it's probably like a SAE or JIC 10 maybe? if there's a taper to it and straight threads... just find something close and jam it on there, assuming you don't want it to come loose just go for it, if the threads gall even better , usually you put antiseise on to make it so it comes apart later but that's not what you are worried about...

 

[jerkyboyxiii]

I capped the egr port on my headers w a stainless steel -10AN cap offa ebay.

 

[gw33gp]

Exhaust temps can get up to 1400F, and any leak through threads isn't enough to worry about...

If your exhaust gas temperature is running at 1400F, you have something wrong and should get it fixed before damage is done. Normally, 1300F is the max you want to see in EGT. The header will not get to that temperature either. I test aircraft engine nuts in a furnace at 1400F. That is is a very bright red hot and our manifolds or headers should never be that hot. They would oxidize and scale to the point the header would eventually disintegrate. It takes metals like Inconel or Waspaloy to survive those temperatures.

 

[scotts90ranger]

I deal in industrial and marine engines for a living, 1400 is up there but within reason of what most engines can handle, I'm talking peak numbers sitting at steady state load and speed... I was just running an engine on the dyno last week and stopped it at 1400 so I didn't hurt anything, have to keep it in closed loop so I couldn't simply add fuel to cool it off... might try adding timing if the NOx emissions don't take too much of a hit... what I do is outside of what most automotive applications will see, hard to drive a car up hill for 8 hours