Hey All,

Just received a P0133 error indicating that my Bank 1 Sensor 1 O2 sensor is getting old and should be replaced. I've got a Canadian 96 4runner limited with the 3.4L, 5spd and 4x4. Is this the sensor slightly upstream from the Cat? I don't have one downstream, and I can't seem to find one any closer to the engine. Also going through the denso website I can't seem to pinpoint the proper part number for this sensor. My research points to DENSO Part # 2344161. Does that seem correct?

Thanks!

 

Here is where I get mine. http://www.sparkplugs.com/Automotive-l134.aspx You can save a few more dollars and post the part number in ebay or amazon if you want. They will get you the correct one. Stay with Denso, dont get a generic sensor, it will only cause problems.

 

Part number is correct. Your truck had a rear sensor from the factory, so somebody may have cut it out, but then you would have a lit CEL. The front one is just forward of the cat.

 

Great! Thanks for the help with that. Ill check that site out, looks like some pretty good deals.

 

Hey Guys,

Ordered up the part and just went under to put some penetrant on the sensor bolts in advance to removing them tomorrow. Noticed that the nuts are definitely gonna need to be replaced. Any ideas what size these might be?

 

They should be M8x 1.25

 

great! thanks

 

Correct...and they're stainless steel.

 

Unfortunately encountered a bit of difficulty with the job. The remnants of the rusted nuts were so degraded that the dissolved under any tool i used. But unfortunately there was still enough solid metal that I can't pull the sensor off and use a die on the bolt. Any ideas on how id go about removing this?

 

Yeah, patience and persistence. Mine were like that. Lots of PB Blaster, use progressively smaller cheap sockets and hammer them on, artistic use of SMALL Vise-Grips (about 5 or 6 inches long, the big ones don't fit). The good news is the studs are MUCH harder than the nuts, so after you crush the nuts to bits, in most cases you can restore the studs.

 

Took a good bit of effort. but I finally got it off. thanks again!

 

Just wanted to say thanks for this post, it helped me figure out which O2 sensor needed replacing on my 99 4x2 V6 auto. Only difference is my part number is 234-4162 vs 4161. Don't know if that's because of the transmission or 2wd.

 

Glad we could help!