Mechanical O2 SIM

Anyone tried these with headers? They are way cheaper than an electronic 02 sim. Supposedly, just moving the 02 sensor further away from the exhaust stream will give you a correct reading. Supposedly, the behind the car sensor is only recognizing flow. http://www.k-series.com/forum/showthread.php?8833-CEL-Problems-Mechanical-02-Sim

 

These worked great on my 2004 Nissan Sentra 2.5L. I had two of them stacked, no CEL... I have heard that the Toyota o2 sensors are more sensitive...

 

A trinket like this worked on my 2007 Scion TC

 

A seller on ebay sells all of his DT headers with these.

 

depending on what type of o2 sensors you have these may or may not work. I cannot comment on the Tacoma but I know they did not work on a Mini Cooper we had without a cat..still had CEL just too sensitive...

 

There is a nice thread here regarding the operation of the rear O2 sensors: http://action.publicbroadcasting.net/cartalk/posts/list/2121926.page.

And Gadget from URD had a good post here:
http://www.tacomaworld.com/forum/performance-tuning/19250-thoughts-o2-simulators.html#post254706
"The signal from the rear O2 sensor is very important for proper engine control.

Those rear sensors are used for more than just checking the health of the cats.

Our simulator is more than your typical rear O2 sim that replaces the signal with an internally generated signal. Ours are carefully calibrated to keep the MIL off, while allowing all the normal operation if important systems and background monitor tests.

The background monitor tests run without your knowledge and test different systems. When these test fail to complete you do not always get a MIL. The rear O2 sensor test is one of these that checks for proper operation of the rear O2 sensors by looking for parallel signals from the front and rear sensors. If the true signal from the rear sensor is not getting through this monitor may not properly clear and you will fail a plug in emission test.

More importantly, the rear sensors are important for normal engine operation. The new style front sensors, air fuel ratio sensors, are wideband units and need to be recalibrated to compensate for sensor degradation as the sensors age. This is done using the rear sensors to recalibrate the front ones.

Those of you that are running Innovate wideband display units know that you have to recalibrate the wideband sensors every so often for a proper reading. The stock uses the signal from the rear sensors to do this.

The rear switching type sensors are very accurate right at 14.7:1 AFR. It uses this point for the recalibration process of the front sensors so it can maintain accurate fuel control.

If you replace the signal from the rear O2 sensor with a falsely generated signal then the recalibration process is skewed to a false signal that may not be anywhere near 14.7:1 AFR.

Our design is carefully calibrated to allow the background monitor tests to properly function and clear so you can pass a plug in emission test and it allows for the proper recalibration of the front air fuel ratio sensors.

Gadget "

Enough to make me think about just trying to go cheap and eliminate the code. With my 2000 Trans Am, we used electronic SIMS, or in the software for the ECU you just eliminated the code so it never threw it, of course GM ECU software is much cheaper than the X1. But, as Gadget writes, there seems to be more at hand with the 2nd Gen ECU.

 

99% of the time it'll work. buy a set of 18mm sparkplug anti-foul adapters ($10 from local parts store)and drill one of them out with 1/2 inch drill bit. Install the sensor into the drilled adapter. Then install both the adaptor and sensor into the unmodded adaptor and screw the whole thing into the exhaust.
What it does is slows the exhaust flow across the sensor so it can read it, either from higher flow exhaust, a worn out cat or lack there of a cat I've had this work on 600whp turbo cars down to a 96 camry with 250,000 miles with the original cat.
FYI... there's 2 adaptors per sensor.