yes they are, I think the ones I have are 3/4" - 1" extensions. I hope that helps! let us know. I'm loving my downpipes...it really is a BEAST now, lol. I'm just waiting on my 3" secondaries (upgrading from the 2.75") and 3" cat-back exhaust from Leistung now!

 

Perhaps another stupid question that will betray the fact that I haven't really been under the car much, but it appears that on the Supersprint primary cat delete I have, there isn't a secondary bung, right?

 

Hmm that's weird, I would think there would be two bungs per side unless they just left two o2 sensors hanging or unplugged them. Which I'm pretty sure would throw a code if not compensated for. Ie, o2 sim or something. Maybe that picture is for a euro model or something that only has one set of o2's. Hop under there and check with a flash light shouldn't be too hard to see them.

 

Generically speaking, as I understand it, the first O2 sensor per bank is used to determine AFR (the amount of unburnt fuel) and pollution exiting the cylinders on that bank. The purpose of the second O2 sensor per bank is to confirm the amount of reduction in pollution reduced by the assumed starter catalyst –catalyst efficiency.

If the second O2 sensor was missing or not installed, the ECU would trigger an implausible signal (no exhaust gas), and assume sensor is dead and throw a “check engine” code. The first O2 sensor is necessary for the engine to run properly.

Most likely, the O2 bugs are offset to a point where they cannot be seen from that perspective. Supporting this theory, is the fact that the only visible O2 bung is lower down on the pipe where the factory second bung would be located. The alternative is that there is really only one bung and they assume it is okay for a check engine light because they are marketed for racing/ off road purposes.

 

yes ^^^ the primary o2 sensor controls closed and open loop feedback to the ecm. That o2 bung on the sprints will utilize the primary o2 sensor and the 2nd one could get disconnected.