I recently head swapped my d16y7 1999 honda civic lx with a y8 head. I got the y8 IM and TB and everything is running good so far. The d16y8 injectors were crap so my friend gave me his h23 injectors. I haven't put the y8 header on yet, though.

Anyways he also sold me his cat for 40 bucks and I want to put my header on but I also need to weld the cat on as well. The only problem is there is nowhere to attach the o2 sensor on the cat. Can anything be done about this? Can I drill a hole in the cat and put an o2 adapter in or something?

 

Anyone?

 

get an O2 sensor bung welded in directly after the catalyst

 

The catalyst being the catalytic converter? I just bought an o2 bung and plan on bringing it to a shop pretty soon. Been looking at pictures of various cats and it looks like some are located directly in the middle of the converter.

Also do I need to buy two rubber gaskets from where the exhaust manifold meets the down pipe. I'll get a diagram.

http://info.rockauto.com/Walker/Deta...l?110-1172.jpg

Based on the diagram it looks like I need 2 of the rubber gaskets (31586)

Is there really any difference between any of those rubber gaskets because it looks like I need part 31619 between the downpipe and cat too and it's more expensive.