modifications > Oxygen Sensor Restrictor

Why did you put the Vibrant J-Style Oxygen Sensor Restrictor on your RS?

My Scorpion downipe has an option to eliminate the catalytic converter. I opted to eliminate it. This fix may also be required with a downpipe that has a high-flow catalytic converter due to the excess flow over the OEM catalytic converter.

After a few years without issues on my RS, a check of the Emissions status on my Cobb Accessport revealed the rear oxygen sensor was "Not Ready". This would prevent me from getting my annual inspection sticker.

In steps the Vibrant J-Style Oxygen Sensor Restrictor to save the day. By placing the rear oxygen sensor further from the exhaust gases in the downpipe, and restricting the flow with an orifice, all is back to normal. The rear oxygen sensor went back to a "Ready" state on the Cobb Accessport after a 20 mile drive.

Date Completed:



- Vibrant 11619 J-Style Oxygen Sensor Restrictor
- Permatex Anti-Seize Lubricant (for hardware)


- 3/8" drive ratchet, 1/2" breaker bar, torque wrench, a few extensions (13mm, 15mm, 17mm, 19mm, 21mm, 7/8" for Oxygen Sensor)
- 10mm ratcheting combination wrench to remove the downpipe hanger bracket
- Phillips-head screwdriver or Chingadera to remove front corner of each black undertray panel to access cross brace under downpipe
- 9,000 lb 4-post lift (optional, but highly recommended!)
*A friend for moral support is always optional.


1. Follow the same steps to remove the downpipe. It took a few hours. I took my time because of taking pictures for this website.
2. Undertray does not have to come off. :)
3. I recommend doing this swap on a cold engine/exhaust. Otherwise you will get roasted a few times in cramp quarters.
4. Only (2) wiring plugs need to be disconnected for this swap (Front/Rear Oxygen sensors).
5. Try and spray both downpipe nuts with a penetrating lube before you remove them.
6. Put anti-seize on both downpipe nuts when you install the Scorpion downpipe.
7. Re-use the factory downpipe gasket at the turbine housing.
8. Torque for downpipe nuts = 35 lb-ft.
9. Make sure to put rear oxygen sensor wiring back in the black clip at the back of the engine to prevent touching the downpipe.
10. Reversible back to stock.