PersianCzar

I have an OEM exhaust on '96. Do I have to remove the heat shield on the cat to get to the sensor? Seems like I can't even get to the bolt.

I also noticed it's a difference size nut on the sensor. What's the best tool to get it off?

Thanks in advance...

DennisMik

iTrader: (2)

Nissan originally screwed the O2 sensor into the cat itself and later used an additional piece of exhaust pipe after the cat to mount the O2 sensor in, so I guess your 96 has the sensor mounted in the cat itself.

I don't know if you have to remove the heat shields, my cat has the piece of pipe and the sensor is out in the open. O2 sensors require a 22 mm wrench, 7/8 inch is about 22.2 mm.

If the sensor isn't frozen in the threads, you can use an open end wrench. That's what I used. A line wrench (also called flare nut wrench) would be better as it is a 4 sided wrench and less likely to round the shoulders.

jfactor

I replaced the same O2 sensor a few months ago. I think it's more of a rock shield seeing as it's on the bottom and yes you need to remove it. Mine was just 4 10mm bolts, piece of cake. I was able to get the sensor off with a crescent wrench without issue, but I second Dennis on the flare nut wrench. It would make your life so much easier but not a must.

Alternatively you could also just cut the wires and use a box wrench to get it off if you don't give a rats **** about keeping it in tact for any reason. This is without a doubt the easiest O2 sensor on the car (non-cali) to replace.

PersianCzar

You guys are awesome!! Thanks for your responses and time, I greatly appreciate it!! There was no info in the searches and this should help someone in the future.

I tapped the sensor bolt and pb blasted over the last 5 days, and it came out smooth as butter. I did have to remove the rock shield, BUT I broke ALL 4 bolts. Hahaha... Bummer!!! Is that thing really that important to put back on? I hear some maximas don't even have that or that aftermarket cats don't have that shield either.

What's you guys take on it?

jholley

iTrader: (13)

I've read members losing that heat shield while replacing the e-brake cables and it hasn't caused them any issues.

CMax03

iTrader: (3)

I can't remember if I removed the heat shields to make room but if I did it's so easy I don't remember if I did or didn't! Do what's necessary and you'll be alright...When you start trying to short cut maintenance procedures that's when you find yourself screwing up all kinds of stuff do to laziness!