Hi all,

I was driving home from work a couple of nights ago when to my chagrin the check engine light appeared.

After a quick stop at my friends house (who is also my mechanic) it turned out to be the dreaded PO420. He then explained that the one or both cats could be bad. I checked the temp of each cat with an IR temp gun. The temp. difference was only about +- 40 degrees, not the +-100 as I was told it should be. After much thought about the options, I decided to purchase a simulator from URD.

For the people who are using these on their Runners; has it lived up to it's claims? Do you noticed a significant in MPGs?

Thanks,

Scott

I have never seen/heard Urd claim the simulator boosts mpg...

Pretty sure it keeps your cel away. However if the o2 sensors were causing you to get terrible mileage, it should fix that.

The front sensor adjusts your air/fuel ratio. The rear sensor is the one that throws the dreaded P0420. The simulators just fool the system into thinking everything is okay and not throw the code. I was looking at getting one if a new rear sensor didn't fix my P0420 code but it seems to have done the trick. I don't remember seeing that the simulator does anything to restore mileage or function to the CAT system.

I know you took readings and if you are convinced the CAT is not working efficiently and it's not the sensor, then may have to go a different route. I decided for $60 +/-, it was worth trying a new sensor and, so far, for me it works. When I looked back at my vehicles history, it had been looked at for CEL's several times. One time it was the MAF and it was found to be dirty and cleaning it fixed the problem. For all of the other issues, the sensor that threw the CEL was replaced and the problem was resolved. So, I know have a somewhat recently cleaned MAF, a newer than original A/F (front) sensor, a newer than original throttle position sensor, and a new rear O2 sensor. So far, no more codes since I put the new O2 on there.

yeah. Simulator is for the rear O2 right? The rear O2 doesn't effect performance at all. It just checks O2 readings after the cat and compares them to the readings of the bank 1 sensor. So, you won't get any performance/mileage gains. But, it sure is nice to get rid of that pesky CEL.

As to your question, I don't have any experience with the simulator. I have heard good things about them both here and on YT though, I think you will be pleased.

I also have a question for you now. Have you ever replaced the rear sensor? Is it original? Have you tested the sensor itself? It's possible that just a new rear sensor would solve your problem, but the simulator should also solve your problem if you prefer to go that route.