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Discussion Starter #1
Hey guys, I wanted to know how you seperate the cat from the exhaust? I was under trying to do my header today and one of the bolts were rounded. Then I looked at undoing the catylic nuts on rear and there doesnt look to be any. If there was, then it was melted totally if that is possible.
 

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The Emo Kid.
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there are no bolts, there are 2 nuts. i had to heat them up with a torch and some WD40 and then lay down and use my foot and whole body to break them loose.
 

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Discussion Starter #3
I meant nuts but there are two connected to the header and two more to the exhaust? Cause on my car I only see two for the header, the one to the exhaust is not there. It looks as though it was welded which is weird since its totally stock.
 

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The Emo Kid.
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are you talking about where the downpipe meets the catalytic converter?

there should be three bolts and nuts where the header meets the downpipe, and 2 nuts where the downpipe meets the cat.

you may have to remove the heatshield from the cat to see them. there is a stud through the cat flange that the nut goes on on the downpipe side. the other side is just the end of the stud that sticks out. if you look towards the back of your car from under the front you should see the nuts on the cat
 

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Discussion Starter #5
No i mean the other side...the nut on the header/cat side is rounded. There are no nuts or bolts on the other side meeting the exhaust. So I cant take off the cat since its attached to the exhaust permanantly. Is this normal?
 

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You're better off taking it to a muffler shop. I heated mine up and they wouldn't budge. Shattered the nut, wasn't pretty. They had to drill the stud out and install a new bolt for me....
 

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The Emo Kid.
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yeah i had that issue. i soaked it in WD overnight, and then torched it, then sprayed more WD on when it was hot and used a 6 point ratchet and my leg to break it free. surprised it worked really... i had almost stripped one of them with a 12 point
 

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LOL They are rounded off because being under the car unprotected and corrosion over time! As soon as I saw that, I said screw it, and took it to a mechanic to do it for me. Knowing that it's a hell of alot easier to install [email protected]'s CS shift stabilizer bracket with the lower cat removed, as well I plan to do a cat-back in the spring, I had the mechanic replace all the the four studs & nuts so I can remove the cat at will on my own after the fact. I even ordered a new set of studs & nuts from Justin, but they didn't get to me in time, so I was stuck buying a set through my mechanic. Now I have an extra set of these things!
 

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I used up a couple of heavy-duty Dremel cutoff wheels cutting and grinding the fused nuts/studs on my G20's exhaust. A slow and sparky process, but I got them cut down to nubs and tapped the cat free with a punch.

Harbor Freight has a cheap cutoff tool that I wish I had picked up last time I was there. The Dremel tool is a real wheezer in comparison.
 

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No the cat shouldn't be welded to the mid pipe. As for the frontpipe to cat nuts, tell me about them...




And after some work with a cold chisel and lump hammer...Btw, I didn't damage the threads on the studs :)

 

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for one of my cars I drilled out the studs from the back, and replaced the stud/nut combo with a couple bolt/nut combos, covered with anti-sieze for reinstallation :-D
 

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Discussion Starter #12
Thanks Mark for the pic. Mine is actually worse than yours. In anycase, my problem is that I cant get the d/p and cat low enough to get a dremel or cutoff wheel in there cleanly. Its gonna be a real bitch just for a header install and I wasnt even the one who stripped it.
 

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I had the same problem as you when I went to put in a header. A ton of rust in that area and the nuts holding the cat to the downpipe were rounded. I ended up just buying a new cat from ebay and a new rear o2 sensor from sparkplugs.com (I couldn't get the old one off the old cat for some reason). I had better luck with the bolts on the other side of the cat because they just snapped off in the right spot and I didn't have to drill anything. But that's probably because I have the stainless exhaust so the rust was only on the cat.

Also removing the stock header was a bitch because the manifold to downpipe connection also had tons of rust and access to that area just sucks. I said screw it and just cut the downpipe in half with an angle grinder where the oil pan is, because there was just no way I could take that thing apart any other way.

Overall it was alot of work and money but probably still less money than having a shop do all the work.
 

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Discussion Starter #14
Yea mang it sucks, too much work. I would cut it but its a stock VE header so its still worth something. In anycase, Im just gonna use WD40, torch then vise grip that bitch. If all else fails then drill it. I want to salvage it!
 
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