Any tips on removing / replacing the O2 sensor? P0420

[sakoluvr]

I got a P0420 code on my wife's 2001 4runner. I hope it's not the catalytic converter. Wondering if I should try replacing the O2 sensor. I cleaned the MAF sensor already.

Denso? What size nuts are on the stud? Any tips for removal besides spraying the nuts for a few days? I wish I could get a 6 pt socket over it. Any tips?

Does the A/F sensor get involved with the P0420 code?

Thanks guys

 

[Kanoe]

Spray the nuts with penetrating oil as you mentioned. If the nuts are too far gone the easiest way to get them off is to get your hands on a set of stripped nut socket type extractors. they will bite down on the rusted remnant of the nut and take it off.

I bought new nuts at the dealer but I remember reading somewhere (likely on here) that VW had nuts that are more resistant to corrosion and will fit.

 

[4rFrog]

Make a 02 sensor simulator for 5 bucks or buy one from URD for a little over a 100. Either way it's cheaper and less headaches than changing a cat and O2 sensor.

http://www.toyota-4runner.org/3rd-gen-t4rs/175242-how-make-your-own-rear-o2-simulator-$5.html

 

[sakoluvr]

The O2 sensor has to be functional for the simulator to work, correct? Is there a Denso O2 sensor part number someone could share?

Anybody run the simulator long term with success?

Does the URD simulator hook up under the rug at drivers seat? Thanks all.

 

[AntleredRuin]

I forget, but I believe it's either 10mm or 12mm. Just hose it down with some PB Blaster a few days beforehand.

 

[gamefreakgc]

The O2 sensor has to be functional for the simulator to work, correct? Is there a Denso O2 sensor part number someone could share?

Anybody run the simulator long term with success?

Does the URD simulator hook up under the rug at drivers seat? Thanks all.

No, the simulator replaces the rear O2. It plugs into the harness near the cat. It works fine long-term, it's a waterproof box with a resistor to modify the signal.

However, the DENSO rear sensor can be had for about $50 on Amazon or the DENSO website so if it is really the sensor, it's not that pricey.

 

[sakoluvr]

This is not a stand off pipe

https://www.urdusa.com/urd-rear-o2-simulator-5vz-fe-3-4l-v6

 

[gamefreakgc]

This not a stand off pipe

https://www.urdusa.com/urd-rear-o2-simulator-5vz-fe-3-4l-v6

Oh, looks like they re-designed it since I've looked at it. In that case it looks like you do need a functional O2 sensor for it to work.

As long as your exhaust doesn't smell like rotten eggs (sulfur smell) then your cat is fine, just replace the rear O2 and drive happy. If the code comes back and your state's smog regulations do not require an emissions monitoring test on a dyno, have the simulator installed instead of a new cat, much cheaper.

 

[theriddler]

I forget, but I believe it's either 10mm or 12mm. Just hose it down with some PB Blaster a few days beforehand.

I was thinking 12mm or 13mm....12mm I think.

+1 on the PB blaster, give it a spray each day for a few days before actually trying to remove the sensor...if it's really rusted on. It will definitely help

Use a high quality socket too if possible, I use Snap On flank drive. Sounds like an odd recommendation but they really help by grabbing rusty bolts and nuts by the sides rather than by the corners, it helps prevent the rounding off.

Last but not least, make sure you buy an OEM Toyota o2 sensor. Yeah it's $180 off of ebay but it'll last you 100k miles...200k in most cases. Beware though, I purchased 2 knock-off o2 sensors off ebay recently thinking they were OEM and I believe they were Chinese. They were even shipped in the OEM boxes and looked like the real thing so be cautious. They cleared the codes for about a month (just outside the 30 day return window) then the code came back and I had to replace them both again. I made sure the new ones were the real deal and I've had no fault codes since.

 

[mtbtim]

<iframe width="560" height="315" src="https://www.youtube.com/embed/CtngAVxJxkE" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe>

 

[theriddler]

<iframe width="560" height="315" src="https://www.youtube.com/embed/CtngAVxJxkE" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe>

Forgot about that, good call! When working on a 3rd Gen step 1 should always be to look for a Timmy video first

 

[sakoluvr]

<iframe width="560" height="315" src="https://www.youtube.com/embed/CtngAVxJxkE" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe>

Yep, thanks Tim. Already viewed that. BTW, the 2001 and 2002 models have 2 cats no matter if they are Cali or not. Also, the O2 sensor is the direct screw in type. The A/F sensor has the flange. The direct screw in sensor is 22mm, but a 7/8" SAE (22.2mm) works fine if no rust. I got mine off last night just to see if I could. My new O2 sensor will be here tomorrow.

No need to spend $100+ on a Toyota O2 sensor. Denso sensors are 50 bucks on Amazon.