I was looking at the installation instructions of the y-pipe on www.seas.ucla.edu/~cheston/ypipe.html and couldn't figure out what the o2 sensor plug was, needed for the installation on 95-98 max's only. Could someone please tell me. THX

 

Whoa there. Which O2 sensor are you talking about. Only the front one needs to be removed. Just follow the harness up about 2.5'. The plug is above the front exhaust manifold behind the radiator. You should be able to get the rear off without unplugging it.

 

I figured that, but I was reading that page and it said that one of the very important tools needed was an o2 sensor plug. It also mentions the o2 sensor plug on step 10 of the install. It says "put in the 02 sensors, along with the anti-seize, along with the 02 sensor plug on the main downpipe.

 

The o2 sensor plug fills in the fourth o2 sensor hole in the y-pipe. If your car is cali spec, then you would have 4 o2 sensors. They do that so they can produce one Y-pipe and sell it to fed and cali spec Maxima owner.

Someone correct me if I'm wrong here.

 

So, since my car is cali-spec I don't need the plug, i just use the 4 o2 sensors that are already there?

 

Yeah, that's the way I understand it.

 

Let me clear this up a little ( I was not clear earlier)

If you're cali-spec, then you have 3 pre-cat o2 sensors. Fed spec only has 2 pre-cat o2 sensors. If you only have 2 o2 sensors, you have to plug the extra hole (or have some wild exhaust sounds, and probably other problems since it is before the cat).

So... the y-pipe will have 3 holes (if it's a universal y) and you will use all three without disconnecting your o2 sensor that is behind the y-pipe (in the B pipe I think).

Does that make sense?

 

Yup, understand completely. Thanks man