How To: Make Your Own Rear O2 Simulator for $5

[Robb235]

Bump, any advice [MENTION=70922]Robb235[/MENTION]

No matter what year 4Runner it is, this is done to the sensor after the catalytic converter (2nd sensor). Don't mess with the first sensor (before the converter) because that controls fueling.

 

[t-man]

Will this work on 4th Gen 4runners? I have an 05 V8.

 

[BearFromOBX]

Just curious why you would use a 250V capacitor on a 5V circuit? Was that just the only one they happen to have in stock at radio shack? A 5V or even 10V capacitor would be plenty for this application.

Because the 250V breakdown tantalum capacitor is commonly available and cheap. Not many electronics stores stock low breakdown voltage tants where this will work perfectly well.

Bear

 

[mtndave]

A big thank you to OP for the write up on this modification. This cured my check engine light when I gutted my stock CAT due to a rattling problem.

Although I was tempted to buy an Eastern CAT, this method is easier than having these units fail and replacing them a few times since I keep my rigs forever.

 

[t-man]

Will this work on 4th Gen 4runners? I have an 05 V8.

[MENTION=70922]Robb235[/MENTION]

 

[Robb235]

[MENTION=70922]Robb235[/MENTION]

I'm pretty sure it will.

 

[t-man]

I'm pretty sure it will.

Thank you.

 

[jklmc]

electrical gurus

need assistance please. no Radio Shack out here in the Pacific. Amazon.com doesn't carry the exact specs from the Radio Shack PNs provided. Can someone "dumb it down" for me? i will be ordering it on Amazon. Just need to know what range of capacitor I can use.

might also try to fab up a O2 sensor spacer for the flange type. (surprised no one tried yet)

i have a gutted CAT and CEL is annoying.

 

[TorqueOfTheDevil]

I wonder if this mod would work with the VVTi 1UZ from a '99 LS400...

I think I'm the only person ever too ADD cats to a truck that didn't come with them from the factory!

:girl:
Also totally unrelated saw this and had to use it.

 

[cvhkhk]

What kind of difference would you notice by installing the simulator and removing the cat?

 

[the great him]

Louder noise, more smell of exhaust...

 

[jklmc]

anyone!?

 

[NWMontanaMan]

Sorry to bump this old thread. I was just wondering if anyone who has done this mod has any left over resistors/caps. I don't have a Radioshack (or anything else, for that matter) anywhere near me and Amazon wants to sell me the parts in packs of 100 or more. PM me if you can help! Thanks all!

 

[shootmymime]

awww snap this is going down.

 

[blackoutt]

[MENTION=101553]t-man[/MENTION] I think this must be the thread you were looking at. I'll try it to see if it works on a 4th gen V8!

Edit: and there we go, $5 in parts for two sensors. Now I have to complete a drive cycle to see if it worked but will update back here.

Edit again: logged a p0606 immediatly and would not clear. Internet research indicated an unknown 02 sensor issue. Removed capacitor and resistor and fault cleared. So in conclusion this does not work on an 07 2uzfe as is. Maybe with a different RC combination?

 

[mmt]

[MENTION=117708]blackoutt[/MENTION] did you ever find a P0420/P0430 solution after your header install?

I got the codes almost immediately then add O2 spacers I still throw a P0430 about once a week. Would you try 1 more spacer on Bank 2?

 

[blackoutt]

[MENTION=117708]blackoutt[/MENTION] did you ever find a P0420/P0430 solution after your header install?

I got the codes almost immediately then add O2 spacers I still throw a P0430 about once a week. Would you try 1 more spacer on Bank 2?

Yes try another spacer on bank 2. I have 3 spacers on both banks. One has 1 drilled + 2 not drilled. The other has 2 drilled + 1 not drilled. Codes took a while to log with only 2 on there but haven't logged in many miles with 3.

 

[Jrsme93]

4th gen

Hey guys, anyone know if this DIY o2 simulator made with a resistor and capacitor will work on a 4th gen V6? Thanks!!

 

[Jszeszko]

Haha, probably. URD has some big description of why only theirs works, but it's probably a load of crap =)

From the site:

Note: Be cautious of O2 sims that replace the rear O2 sensor with a falsely gererated signal.

Toyota started using a wideband type O2 sensor (air/fuel ratio) in the front position for better engine control. These wideband type sensors need to be recalibrated from time to time by the ECU. The ECU uses the rear sensors for this recalibration process. The ECU cannot properly recalibrate the wideband sensor using a falsely generated signal. This process is explained here, US Patent 5706654.

Use only a URD O2 Sensor Simulator on these vehicles to avoid poor performance, drivability issues and poor MPG.

I know this post is 3 years old, but I completed the install of the $5 sim and it did keep the check engine light on, BUT.. being a 2000 california cat car, it would not allow the O2 sensor or catalyst system to initiate, no matter the miles, it would never ready up, thus not passing emissions. while it did not through a check engine light, the simulator was not the fix for my truck. urd simulator it is

 

[Jon]

Mine's been fine for a year now, no CEL. Just thinking outside the box but most secondary o2 sensors are just looking for the same ballpark return with minimal fluctuation. My GTO has catless headers and I tried the trick that worked on my Subby which is just using the extender to pull the sensor out of the main stream and that did not work.

So I went on ebay and ordered 100 capacitors for 3$(because it was only $3) and 8 resistors for $6.

I'm going to make the same harness for the two down streams on the GTO and my Titan which has the infamous exhaust manifold cracks and will of course need catless headers because all v8s do. Even some v6s. and 2JZGTEs.... **** cats

Let ya know how it turns out!