URD rear o2 sim / calibrator / wiring

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Jul 30, 2016
pensacola fl.
This thing is kind of spendy until you have it and install it. I've had it a week, testing and stuff. It's the universal item, dual banks.

It has 4 pots, 2 for each bank, 1 gain- voltage, and 1 filter- response time.

It comes with a dummy plug so you can bridge the ins and outs to function as unaltered if you want to remove it, because, of course it's for off-road only.
The box is good, the wire is good.

For this vvti 4.7 the reference labeled tan wire needs to go to ground along with the black ground.

I went with wiring both grounds and power through the antenna plug next door, A30 connector position 5= white black ground and position 17 grey= +12 ACC so not to disturb the ECU plugs much. Be careful you pick a good ACC wire. I debated grounding to the body or a harness. Went with the harness option.

For the LC vvti the bank 1 = OBX1 is in ecu connector E5 position 18, black wire. For bank 2 = OBX2 is ECU connector E6 position 33 white wire. Probably the same for the LX vvti
I did not check to see if it would function without an output from the rear o2 to the box.
It functions very well and the voltages are right where I want them. You want to watch full load, fuel cut, and hot idle. Set it and forget it.

You need the o2 sensor heater circuit functioning normally.

urd instructions + notes attached, and pic in the pdf.


  • urd wiring pages with notes..pdf
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Where do you find this? I'm not seeing anything on the urdusa.com website.
they discontinued it. They say there are making a better one that more accurately controls units with wide and narrow band o2 sensors.

read this page URD O2 Sensor Calibrator - Underdog Racing Development - https://urdusa.com/urd-o2-sensor-calibrator/
at the bottom they write, A dual-channel unit for dual bank systems is in development.
-this would be for toyota vehicles which they single out

they then single out afr calibrators in conjunction with maf and closed/open loop manipulators. This isn't really for vvti non forced induction swaps.

hate to say it, but it appears like they just aren't going to have an item that handles 2 channel rear calibrators on the toyota with twin afr and narrow band o2s.

I am suspicious though that the single channel o2 calibrator isn't the exact same as the old version, except you'd need two of them for 500$ one for each rear narrow band o2 when the original twin was 149$.
I'm not liking them much (urd) they don't post pics, answer emails, and they don't post their own reviews.

finding a used one from a tacoma guy would be the best bet, sheer number wise. tundra, 4 runner and sequoia guys second.

The product is great though. It's soldered into my ecu and has a jumper to swap back in the cats whenever.
it would work either cat less or compromised cats.
Everything is getting way more expensive, dramatically.

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