ETRNL

i have searched an didnt turn up any results i hate the restrictive Cali dual cats and would like to go to a single high flow (i really would like to just run a muffler but..) to free up some power but i havent found a definite answer is it can be done and still read correctly when it is hooked up yearly at the inspection sticker place.

TheDurk

First, in NJ, and I suspect most states that hook directly to the OBDII computer, their computer goes to a VIN database and gets the emissions standards from there.

Second, "born Cali., forever Cali." It is illegal to alter the specs of the original emissions system under Federal Law.

Third, in 2001 there was no more Çali.' standard. All 4Runners for all 50 states used the two-cat system formerly known as Cali. So you would have to impersonate an earlier year.

Fourth, the two-cat system uses an A/F sensor in the front, which varies current rather than voltage. The only way to get a clean reading would be to change back to an O2 sensor and a new ECU from a 2000 and earlier 49-state car. NJ's computer would catch this easy based on what I see in the printouts I get every other year. I can't say about LA.

The other alternative is keep your A/F and ECU and install a URD simulator. I have watched carefully for several years and I have not seen a report of anyone using these in a state with computerized OBDII emissions testing. I don't know if that is because people are reluctant to post on this or because nobody is doing it. I would like to know (out of simple curiosity, of course).

ETRNL

well has anyone posted if a single high flow cat would do the same job of 2 stock cats? if i had to run an urd simulator that is fine as long as i checks out at the inspection station. but i too have not seen any reports about emissions testing and whether or not they will pass.

i found this one there website "DO NOT USE ON A PUBLIC ROAD OR HIGHWAY ANYWHERE IN THE UNITED STATES. and Sensor Simulators are not CARB Approved, and are never to be used on Pollution Controlled Vehicles or on Public Highways"

is this there legal disclaimer for when a vehicle fails a check it is not their fault?
i have no problems running this setup and then swapping to stock once a year for a check up. is it legal? probably not, do i care? no cause i guarantee that my 89 chevy has worse emissions than my 4runner ever will but all they check is the lights on it.

coinball

I just put the URD simulator on my 02 4Runner. I put in a set of TRD headers and had to weld an extension on the 2nd cat pipe to meet the TRD header outlet; the headers replace the 1st cat, which was enough to give me a CEL. I tried the spark plug anti-fouler trick, but no success; so I picked up the URD. Been fine since, we'll see what NC emissions have to say about it...

ETRNL

cool that is what i need to know.

Yukute

Its been half a year since the last post. Is there any news on this? I have a Cali vehicle in Colorado now and am getting codes. I don't want to spend $2k replacing Cali stuff and would like to upgrade my exhaust.

So, any news to report?

mswenso1

Hey Yukute, I have a Cali 4runner in Colorado too. Was getting codes after having it for a year or so (140-150k miles) and looked into this. Found out that Colorado is really astute with their testing so decided to keep it stock. Found the correct front sensor (A/F sensor) online for $80 bucks. Cleared all the codes for about three months, then started up again...started to run 91 octain and did a couple good fuel cleaners and have been great ever since.....IMHO its hard to get past keeping the exhaust stock here unless you want to spend the $$$$. Good luck

ETRNL

almost a year later.... i didnt do anything for a few months until one night i got out of my truck and i saw a glow under my truck. The cats.... i said screw it i had enough. i let it cool down overnight and unbolted my cats. i then continued to take a 2" holesaw on an extension to the center of the cats drilling straight through the material inside that i decided to call "Yotacrete" cause a torch would not melt it and a steel pipe and a sledge just barely dented it. So i completely emptied out the internals of both cats bolted them back on, and installed a URD simulator. The computer has been happy since Aug. of last year. Passed the inspection with the obdII port. Louisiana and Oregon (where i live now) do not do a tailpipe test. THIS WILL NOT PASS A TAILPIPE TEST. zero problems so far.

ojairunner

The URD saved my a$$ as well. I am so glad that they created that simulator.
I pass CA smog with no problem (I have 2 cats - rear was throwing cel) and have no known side effects from having it hooked up.

SoCal

What is a URD?

ojairunner

http://www.urdusa.com/Electronics-Re...170/index.html

smogman

absolutly correct. it will pass no problem as long as there is no tailpipe test. Soon Cali is going to no tailpipe test on 2000 and new vehicles. this will be in the next few years. just and obd2 test and no tailpipe.

Not sure what URD stands for but he is talking about a MIL elliminator. These have been around for years. I'm sure they have different name by now. Just a plug with some resistors to tell the computer the rear o2 sensor is working. The computer in turn thinks the cat is working and keeps the light off for a catalyst code.

The glowing cat you speak of is related to a misfire and raw gas dumping into it. That means your cat is working good and you have another problem in front of the cat.

Autotek is giving away 4 free Smog Checks a month.
"Like" our page on facebook to enter
http://www.facebook.com/916smog
http://916smog.com
916-723-7664
8633 Antelope North Rd.
Antelope, CA, 95843

ETRNL

URD stands for Underground Racing Development, the company that makes/made the plug in box. It is not just resistors in a box, it takes the signal the O2 sensor is sending and modifies it to specs that makes the computer happy. My engine was running fine when my cats started glowing. Personally I blame it on the 10% ethanol blend BS that is at the pumps today. Corn is to eat, not for vehicles to run on.

smogman

So I guess it uses magic to modify it because it's in a box? With a cat, the o2 sensor in the back puts out approx .45v with no cat it mirrors the front o2 sensor varying for .01-.99v. If this has a wide band o2, it does not mirror the same voltage but the computer still looks for .45 volts on the rear sensor. problem is, some manufactures calibrate the wide band signal a steady voltage of .45 will not allow the o2 monitor to run. but still the rear o2 has to put out .45 volts adverage or it will set a cat efficency code. difference is your box uses the factory 02 sensor and adds resistors, the old style just uses resistors from the line voltage not the sensor so it never varies. But still a resistor. There is no magic in there. Maybe a diode too. Not rocket science.

10% methanol is why your cat is glowing? Wouldn't everyones cat glow? Your catalytic converter is just like a camp fire, the more raw fuel H.C. or Partially burn't fuel C.O. you put in it the hotter it gets. To test a Cat on a vehicle thats running perfect, sometimes you have to pull a spark plug wire to heat the cat up enough to test the inlet and output temperatures. Less than 10% temp rise from the front to the back and the cat is not working at all. I bet if you looked your cat it was glowing and so was the pipe behind it, but the pipe in front of the cat was not. If it was glowing from the manifold/headers back to the cat the timing was retarded.
Just because you made your Cat not glow red anymore, doesn't mean you fixed the problem. it just means you covered it up. sorry if you thought what I was telling you was my opinion, but it's actually fact. This is why Toyota does not hollow out converters in the service department, they fix the problem.

http://tinyurl.com/3wgl77y

Autotek is giving away 4 free Smog Checks a month.
"Like" our page on facebook to enter

http://www.facebook.com/916smog

http://916smog.com

916-723-7664
8633 Antelope North Rd.
Antelope, CA, 95843

ETRNL

That's cool smogman. Either way computer is happy and truck is running good. Cats are no longer a problem and never will be again on my truck. Plus my truck will no longer smell like rotten eggs. As for the box, I am sure there is a resistor or two in there, signal modification is pretty simple.

rideexileex

iTrader: (1)

I hope you mean only changing voltages... "signals" is a 4 year+ ballgame my friend...

ETRNL

Yes, voltage from sensor. Aka input, signal, source.. many names.