header bolt size o2 sensor

jhoffmanjr1968 · Post by **jhoffmanjr1968** » Sat Sep 29, 2007 6:25 pm

I know have my haeader and complete exhaust put on the car.......but I can't start it yet because of the nice size hole where a 02 sensor goes. Does anyone know waht size it is. 18 mm 5/8 and 16mm won't fit. I'm assuming it could be 17 but I couldn't find it anywhere so far.
Thanks for any help.

So Cal Mark · Post by **So Cal Mark** » Sat Sep 29, 2007 6:44 pm

screw a spark plug in the hole.

jhoffmanjr1968 · Post by **jhoffmanjr1968** » Sat Sep 29, 2007 9:28 pm

Thanks Mark, that actually crossed my mind, but I wasn't sure of the size on that either.

jhoffmanjr1968 · Post by **jhoffmanjr1968** » Sun Sep 30, 2007 10:55 am

well bought a spark plug this morning. it didn't work. quite a bit too small. I bought a fiat spark plug, any suggestions?
Thanks

So Cal Mark · Post by **So Cal Mark** » Sun Sep 30, 2007 12:27 pm

there are two sizes of spark plugs, 14mm and 18mm

jhoffmanjr1968 · Post by **jhoffmanjr1968** » Sun Sep 30, 2007 4:12 pm

Hey Mark,
picked up a 18mm spark plug.... still doesn't fit. I can only guess this is 17mm. and it has been impossible so far to find one. I do have the machine shop where I had the head rebuilt. probably try them tomorrow.
thanks

So Cal Mark · Post by **So Cal Mark** » Sun Sep 30, 2007 4:35 pm

the O2 sensor goes in the exhaust manifold, if you're talking about a hole in the cylinder head that's something completely different. What year engine and cylinder head do you have?

manoa matt · Post by **manoa matt** » Sun Sep 30, 2007 8:44 pm

Most muffler shops should have an O2 sensor plug for that hole. Did you have a cat converter on the old system? There maybe a plug you could take from your old cat.

An auto parts store might also have that plug. If not just buy a cheap O2 sensor for about $20.

Matt

jhoffmanjr1968 · Post by **jhoffmanjr1968** » Sun Sep 30, 2007 9:42 pm

Mark,
I have a 1980 carbureted model. 2l block, 1800 head. performance cams, 34 adf.got the header from iap. it's the injected header with the lambda port. the rest of the exhaust from Bruce's. Matt had mentioned a bolt from the cat converter. I will have to check my work tomorrow. put the whole exhaust in our scrap metal bin. My neighbor runs a tire joint/garage. he said he will find something as well. hopefully after tomorrow I should figure out something.

jhoffmanjr1968 · Post by **jhoffmanjr1968** » Tue Oct 02, 2007 10:08 am

well....still no luck. my neighbor says he can get me a 18mm self tapping to put in there. rather not do that if I can help it. I mentioned o2 sensor but its the lambda for the injected models. not sure if 02 and lambda are the same thing.
a couple of mechanics at my work said to go to a plumbing supply house, they figured I could get a plug for it there. they said it might be pipe threading. I'm ready to try anything at this point.

So Cal Mark · Post by **So Cal Mark** » Tue Oct 02, 2007 10:12 am

lambda and o2 sensors are the same. I'd complain to IAP and see what they say. Sounds like they welded the wrong fitting in

jhoffmanjr1968 · Post by **jhoffmanjr1968** » Tue Oct 02, 2007 10:28 am

Hey mark, called them up. it was probably the 3rd or 4th call. finally got hold of someone who knew what he was talking about. he looked it up in the system.......said they sell the plug for it!!! unbelievable! Thats unbelievable in a bad way. he said it should be here in about two days. we will see if it works. I appreciate the help. it's nice to be able to get hold of people who have serious knowledge of the fiat automobile.
This is my 5th that I have owned. three x19's and two spiders.

Mark_vaughn · Post by **Mark_vaughn** » Tue Oct 02, 2007 10:46 am

If you are not ever planning to use it just use some JB Weld and seal it up for good.