Just thought someone may be dealing with some of the same challenges that I am. I put on a header with a catless downpipe and started throwing CELs for the #2 O2 sensor. Some vendors will try and sell you an O2 simulator. Thats cool, but if you would like to fix the problem for under $3.00 (yes, thats three dollars), then read on. Go to your local chain store auto parts store and as them where their "spark plug anti foulers" are. I know you are thinking I took one too many huffs out of my nitrous bottle, but stick with me here. If they have the "Help" brand, look for part number 410002. Buy a two pack. Take one of them and drill the inside out with a 1/2" drill bit. Screw your O2 sensor into that one and then screw both of them into the second (unmodified) one that you bought. Then put the whole assembly into your downpipe and plug in the O2. In my case, my downpipe did not have a 02 bung for the rear sensor, so I welded drilled a hole in the downpipe and welded the bung right to the downpipe. Whaala, no more CEL. Mike

 

I juest added a couple of metal washers, worked just as well, cost me $1.50

 

I just got the rear O2 sensor disabled when I got tuned ($0)

 

what??!??!??!! so you are saying that it is easier to just get it disabled with a tune? i've never heard of such a blasphemous thing.



that's what i did too.

 

Lmao!!!

 

keep in mide it only turns of the code display, it doesn't actually stop the car from reading it and therefor will still hinder your performance......but you won't throw a code lol

 

Well if it does "hinder" performance, I sure as hell can't feel it!

 

the rear o2 will not "hinder" performance. it's sole job is to let the computer know if he catalytic convertor is working or not.

 

No...I believe it also affects whether the mixture is too lean or too rich....

I had thought the O2 sensor was ahead of the cat....

 

Exactly

 

the front o2 sensor does air/fuel (although not very well), the rear o2 sensor only tells if the cat is working or not. that's why the front o2 sensor costs more when you buy one.

 

Soccer1061287,

If you want to turn it off completely, let me know and I'll turn it off with hptuners for you if you still have a problem.