Rear O2's

[RyanS197]

Im going to be installing dynatech LT's with these cats soon
http://www.car-sound.com/02product/displayuniversal.asp?universal=54956
Im thinking it doesnt really matter but i wanted to be sure before i start cutting and welding.

Does it matter where the rear O2's go? I gather they should be on the outlet side but does it matter how far from the cat?

 

[ZmanM3]

I haven't had working O2 sensors in a long time. JDM cut them out in the tune.

 

[Big Daddy]

Does it matter where the rear O2's go?

I concur with ZmanM3, if you are or will be running a tune they will more than likely be off, so no need to reinstall them unless you have a reason to. In that case, I would locate them as close to where the factory locations are.

 

[ZmanM3]

I concur with ZmanM3, if you are or will be running a tune they will more than likely be off, so no need to reinstall them unless you have a reason to. In that case, I would locate them as close to where the factory locations are.

I just have the stockers in to fill the hole and in case I ever have to pass a visual inspection.

 

[JibStyle]

My friend installed my dynatech LTs. If he did something wrong with the O2 sensors could this be why my check engine light always comes on? And the headers are great

 

[RyanS197]

Im gonna make a set of O/R pipe to run most of the time, but i need to pass emissions once every couple of years so i need a functioning cat set up.

That said i really dont think it matters as long as they are after the cats. I was confusing myself thinking the stock setup has them at the inlet of the cats for some dumbass reason. But i remember now they are mounted at the center of the cats.

 

[RyanS197]

My friend installed my dynatech LTs. If he did something wrong with the O2 sensors could this be why my check engine light always comes on? And the headers are great

Are you running off road or catted mid pipe? If its off road then the rear O2's need to be turned off in the tune or the CEL will come on.

 

[Big Daddy]

I just have the stockers in to fill the hole and in case I ever have to pass a visual inspection.

Ditto

 

[Big Daddy]

...i need to pass emissions once every couple of years so i need a functioning cat set up.

Not necessary.

Have your tuner supply you with a tune for emissions.

 

[RyanS197]

Yeah man this thread was a major brain fumble on my part. I added it to the technical thread of the day a day or 2 ago. I was hoping it would just die and go away but it looks like its gonna haunt me in my sleep.