Which Oil Drain Plug size fits Invidia Up-pipe EGT sensor location?

[BillyJoe]

I have done some research on what to do with the EGT sensor "location" on my Invidia Catless up-pipe. I have decided to not use the OEM sensor, but instead to plug it with what people have been using on this forum, an oil drain bolt/plug. From what I've read, the correct size for my application would be M12X1.25. However, when I went to the local Autozone to pick up the oil drain plug in that size, I can only hand tighten it about 1/3 of the way down. I didn't however use a wrench to try to work it in more, since i didn't want to strip/force the bolt into my up-pipe.

 

What i want to know is, do I have the right size?

 

and

 

Is it normal to not be able to hand-tighten down to bolt any further than about a 1/3 of the way? (for those who have already done this mod, what were you experiences?)

 

I am having the stage 2 components installed tomorrow at a subaru dealer, so maybe they'll have something there. Thanks ahead of time for your help!

 

Stan

[rao]

Spark plug size -

 

M18x1.5

[BillyJoe]

sweet...thanks Rob, i'll check it out tomorrow.

[GTTuner]

I think rao is thinking of the 02 sensor size. It is def 12mm but not sure if it is 1.5 or 1.75 pitch thread.

 

The last one of those I installed did the same thing, after three turns it was very tight.

[rao]

I was talking about the 02 sensor, not the EGT sensor

[BillyJoe]

Yeah you're right, I do believe the EGT sensor in the up-pipe is 12mm. I would know for sure but i didn't end up going stage 2 this past weekend, it was getting late after my TGV deletes install, so i told the mechanic to go home and enjoy his saturday. So it's next week to go stage 2 for me. So i was not able to check if my 12mmX1.25 drain plug will fit right.

 

At least we know its 12mm, now let's hope its 1.25 pitch thread or 1.50, because i can find drain plugs for those sized easily. I'll let you know what i find out.

 

Thanks for your responses! keep em coming!

[BillyJoe]

FYI, the size of the plug for the EGT sensor on an Invidia UP catless is M12 X 1.5

 

Now the search continues for the right length! Thanks for all your responses.

[FPerron]

It's also important to use a plug that's made from close to the same alloy as the UP. Otherwise, the plug and the pipe will expand at different rates and the plug will blow out. Ask me how I know:redface:

[caramall2]

This might not be your case, but for others....

 

If you're talking the smaller EGT bungs (e.g. they're about 3/8" wide at the opening)....

 

EGT sensors are usually 1/4" NPT (Nat Pipe Thread taper)...this is a special plug that tapers down (not a regular bolt, etc.). I know because I struggle with this as well. Go to a good bolt place and tell them you need a 1/4" NPT pipe plug (they're about 1/4" long or so).

 

NPT is used on piping for heating systems, etc, from what I understand....like your black iron piping you see in a boiler room. The threads actually "taper" a bit so as you tighten they get to a point you can't tighten any more.

[jus2phast4uLGT]

great post guys thanx..i just ordered a greddy up-pipe with egt "dur"..shoulda got it w/ out the egt bung since i hear the egt probes can blow out (if installed) and blow a turbo :/

[croll326]

I called Invidia today and from what I could understand the person I talked to said M12x1.5 but I asked him what type of thread it was and he was clueless.

 

I think www.mcmaster.com would have something.

 

From what I am finding 1.5 thread pitch is not available in a stainless steel bolt, I am pretty sure the UP is 304 stainless....ill keep looking

 

Any worries using a zinc plated bolt or plain steel that will rust?

 

I am thinking after I put the bolt in I will have the bolt welded in at a local fab shop.

 

Why not just get a M12x1.5 set screw. It doesnt have a head on it so if you get a short one you can just tighten in as far at it will go before it seats itself in the bottom of the hole.

 

http://www.mcmaster.com/#set-screws/=6qz0v2

[croll326]

I went to a local parts store today and came away with nothing. A 1/4" NPT plug wouldnt even thread in. The M12's only go in about 3 threads then bind. What do I do now? Is it ok to take a M12 and thread it in as far as possible and let it be? I was thinking about getting the hole welded shut instead of using a bolt. Thoughts?

[croll326]

I installed the up pipe with the EGT sensor and am having second thoughts. I want to plug the hole!

[N.Y.X.]

I know this is an old thread but I am getting conflicting sizes, it says M12x1.5 but here it says M12x1.25...

12mmx1.25

From: http://legacygt.com/forums/showthread.php/size-egt-sensor-up-pipe-39150.html

 

And has anyone found a good Stainless Steel bolt to use? Thank you.