Im about to turbo my 97 GSR and I was looking at schematics for a o2 simulator so I could fool the OBD2 ecu in to thinking that I had a Cat. I want to run a full 3" exhaust with a "Test Pipe". I would still have the second O2 for visual purposes but I would have this "o2 Simulator" interfaced with the signal wire. My question to you would be is this possible and am I on to something for all those going through emissions? Once again I would NOT have a Cat. just a Test pipe and this electronic device to simulate the o2 voltages that the ecu would be looking for?
Here is the site I came across: http://www.mkiv.com/techarticles/oxy...sor_simulator/
It looks simple enough and the parts are available at radioshack.

 

I remember someone else selling an O2 simulator for around 20 or so...

 

So It will work? Im not trying to buy one I want to make it so I can run a test pipe on my emissions controlled vehicle

 

Well I tried 2 different ones...a mechanical one and an electronic one. Both didnt work

 

oh ok Ill guess ill still give it a try and let you know the outcome...hell itll still be fun to make :D

 

i'v tried to put together that same exact simulator, its nothing but a 555 timer which works like a turn signal relay it flips on off small voltage signal that supposed to work. i tested it on my friends rsx where we tried to simulate a signal so check engine light would go off since his header removes a cat. he still has the secondary sensor attached to the header but when we attached that simulator instead of reading of oxygen sensor different cel came up saying that heat sensor error. heat sensor does not match the reading of oxygen sensor

next thing to try is a spark plug extension, but im not sure if it will help your situation

 

Spark plug non-fouler...the "extension", is the mechanical one I used. It didnt work. Still threw a code. The o2 sim I got from a website was spliced inline to the sensor wires didnt work either. I never checked which code it was. I was just looking to see if it would throw a code and it did.