'oo gsr, i did the ebay thing, the same way ever tuners horror story begins...
i bought an obx high flow cat. of course, 63k on the car, the stock cat was a bitch to get out. i noticed the o2 sensor was in a different place, in front of the cat instead of at the other end. i figure im going to get a CEL either way, so i put it in. my luck, they must have shortened or lengthened the tubing somewhere along the line, the o2 sensor was in contact with the chassis. it was late oclock at this point so i had to drive it home the way it was. ive since unplugged the o2 and put a plug in to lose the vibration shooting from the motor all the way to my steering wheel. the car definitely shows improvement, but theres gotta be a catch other than that stomach turning lil yellow light i now have glaring at me everytime i start the car. what are the consequences based on stories experiences or any other knowledge of the secondary o2 sensors? mpg? performance? please let me know what you think...

 

if the o2 sensor bung is at the opposite end then you bought the wrong cat.. and without an o2 sensor your gonna get shitty gas mileage and throw a code.. good luck

 

The secondary sensor only monitors for emissions reasons.

 

primary sensor hasnt moved, its at the rear of the manifold, the secondary bung is now within four inches of the primary. ive looked around on HAN for hours looking for a specific answer to whether or not the secondary sensor really does affect performance but its about what ive got here, six of one half dozen of the other....

 

Trust me, it isn't used for performance reasons. The two o2 sensors are identical on most Hondas. Now think to yourself "What could possibly change in oxygen readings in 8 inches of pipe which happens to be a catalytic converter?" Nothing related to performance.

 

anybody tried the o2 simulators? its one of those cheap azz ebay pieces that i dont dare to buy, but at the same time, its so cheap if i do try it ill only be out 13 dollars...

 

^-- that dude loves his GS-R :kiss:

 

o2 sims work, all it does is tell the pcm what it wants to see coming from that o2 sensor. so no cel

 

If you have OBD2, they matter. It with through a code and run open loop if don't have a good read on one. I had to run a O2 sim on my 96 EK turbo. I was still running OBD2. An O2 sim would fix that for you. I have one I no longer needed if your in the market for one. Only the best - Casper Electronics. Let me know.