Hopefully this is not a dumb question but I just saw another post of someone saying for the T1R test pipe you need an 02 simulator? What is that and what is it for?

My spoon has an 02 bung on it. Don't I just unscrew it from the catalytic converter and screw it into the new test pipe?

 

An O2 simulator will be needed for any test pipe if you have an OEM ECU with the backup fuse installed. All OBDII ECUs compare the readings from the primary and secondary O2 sensors to make sure the catalytic converter is performing properly. The O2 simulator tricks the ECU into thinking everything is working.

 

Thanks for the information.. I guess I'll just not mess with putting on the test pipe then.

 

You can put on the test pipe with a "mechanical" O2 simulator with no problems. This simulator moves the sensor just far enough away from the stream of exhaust that you will not get a CEL. I have had one on for a couple of weeks now without a problem. See here for the thread on this device. It's relatively simple and primitive but it does work. Some owners have had this for a couple thousand miles.
https://www.s2ki.com/forums/index.php?showtopic=229959

 

Or you can just leave the catalytic converter in place.

 

But a missing downstream O2S should only set a CEL. It shouldn't affect driveability, as the downstream O2S functions solely as a catalytic converter efficiency indicator. The upstream O2S is used to 'bounce' AFR from rich to lean and back, to let the catalytic converter do its job - oxidation and reduction.

 

I wouldn't disagree, but my experience before getting my O2 simulator was that I had a significant loss in fuel economy. My only guess is that the ECU dumped extra fuel in an attempt to heat up the cat (that wasn't there).

 

Didn't know there were further replies.

Just checked out that 02 bung extension thing... my one question is this... if you drill out one of the anti-foulers, doesnt it make it smooth inside? How do you make it so that you can thread the 02 sensor in? Or is it tight enough for you to just push the 02 sensor in there?

 

You do not drill out the thread, only the part that the O2 sensor tip goes into. Look at that thread I linked and you'll see pictures showing how it's done.