so the previous owner of my rig (in my possession for 2 months) thought it would be smart to weld in the O2 sensor. i crawled underneath the 4runner with a propane torch, a bottle of PB blaster, and a big breaker ready to fight rust and replace the old sensor with a brand new one. lo and behold i sure wasn't prepared to see the sensor welded in. why, oh why!?!?

my question is this: there are a ton of 3.0 4runners in the junkyards out here. if i go pull an exhaust pipe out of that and cut the flange out, does anyone know if that will fit my denso sensor for for 4 cyl?

I would got to a local exhaust shop. the o2 sensor flange cost me like 6 bucks. i had to cut the old one out cuz the p.o. welded mine too!

Sorry that was me that welded it in.

Lol.. jk. Yea don't waste your time at the junkyard buying an old rusted pipe. Go to an exhaust shop, they should have plenty. If anything bring your new sensor to make sure the one they give you is the right threading

Another vote for making it the exhaust shop's problem.

Fink

Interesting all the oxygen sensors I have don`t have any threads .

Just a flange with 2 studs the same style on my 22rec engine the same on my 3.4 engine the 7mGTE is also like that.

Are you sure the studs just did not rust away giving it the appearance of the O2 sensor being welded. I have seen a few like that.

I am almost sure the heat needed to make a leak free weld would compromise the electrical connection at least.

Now the studs are M8 x1.25 x40mm which was what I had when I made new flanges if the studs are to long after installing the O2 sensor I just cut them shorter.

That is interesting. toy3sgte must be an idiot or some type of terrorist! But yes. My mistake. I had wideband O2 sensors pictured in my head for some reason.

They're the 2 bolt flange style unless somebody installed a universal sensor. And yeah, the heat from making a tight weld will definitely cook the sensor! I left exhaust shop with the check engine light on cuz the guys welded it into the my new system on the 3.0.