The car is a '99 GSR.
It won't pass inspection because it's throwing a CEL due to the T1R test pipe that's on the car. Is there a workaround to fool the ECU that both O2 sensors are on the car without having to get another cat?

The GSR cat had both O2 sensors in it. Now 1 of the 02 sensors is in the DC JDM 4-1 header (because it's a Type-R header) and the other is in my garage due to the T1R 2.5" test pipe and T1R 2.5" exhaust.

In order to pass inspection I guess I need a CAT with one (1) O2 bung but what about the O2 sensor that's in the JDM ITR header? The header says on it "not street legal or not for street use" (or something like that). So I 'm not sure if that O2 sensor is actually even helping at all or reading high # of CO particles..

If anyone has a JDM ITR header with 2.5" collector, and a 2.5" ITR exhaust, please let me know what CAT you use without throwing any CEL's and if you pass emissions inspection.

BTW, I measured my T1R test pipe and it's exactly 16.5". Can I get a Carsound that long? Someone had told me they come in 17" besides 12 & 13". Can a 17" Carsound be made to fit? Does SMSP still make custom CATs? I send him an e-mail yesterday and haven't heard anything. I hope he can help me out because I need to get the car back on the road very soon. Thanks in advance for any advice you can give.

Harry

 

the way it works is the first o2 is the one that controls the engine, the downstream(2nd o2) checks to see if it has a leaner value than the upstream. go down to an advanced auto and get 2 spark plug foulers. drill out the hole in the bottom of 1 of the foulers big enough for the o2 sensor to fit through it. then take the second unmodified fouler and thread it onto the sensor and other fouler. then screw this assembly into the test pipe and plug in the wires for the downstream o2. leave the upstream o2 hooked up and reset the ecu by pulling the fuses or disconnecting the battery for a few minutes. hook everything back up and fire up the car. this works by limiting the gases that get to the downstream o2 so that it thinks the cat is doing its job even though its not there. this works on about 50% of cars but its only a few dollars and if it works then it was well worth it. give it a try and let me know how it works out.

 

Thanks for the workaround! It's definitely worth a shot.

Question: How do I screw in the downstream O2 sensor and foulers into the Test Pipe? The T1R test pipe doesn't have any O2 bungs. It's a really nice SS resonated pipe. I don't want to ruin it. I was hoping I could do something temporarily to pass inspection and restore the TP in its original state.

Are you saying drill a hole in the TP and leave that concuption in permanently? My only fear is that it may not work because you said it only works 50% of the time and after all that I 'll have a hole in my TP that I take so much pride in

 

usually when you buy a weld in o2 bung it comes with a plug. if it doesnt work then you put the plug in and call it a day. its not like you can see the test pipe either way. and yes i was saying leave it in perminantly so you dont have the check engine light on all the time. i was only told it worked 50% of the time, ive used it twice and it worked 100% both times.