does anyone know if on a 97 cat the o2 sensor is on it or after it. on my jeep the guy that had it before me jb welded the 02 sensor to the cat ! Now that i have a p0138 code im trying to figure out the best way to go about this and also the cheapest. heres a pic

 

Bump. Anyone?

 

Is it like a '98?

 

Should be. Does it have to be on the cat? Or can I put a pipe right after it with a o2 sensor

 

Hum, don't know, anybody?

 

Yes anyone? the cel is killing me.

 

The downstream O2 should have NO effect on engine performance.

 

Hmm someone told me it will affect air/fuel mxture. He could be wrong. I need to fix this tho due to illinois emissions. Don't want to spend a lot of cash for a new cat and o2 sensor.

 

Think you've got no alternative. May as well fork out the dough, have it done right and have something you know will pass state inspection.

 

There's no way I could put a little piece of pipe with an o2 bung behind the cat and put a new sensor in?

 

U could try it and see. The upstream O2 sensor(s) control the air/fuel ratio, not the downstream (after cat) O2. Either O2 can trigger a CEL.

 

Your 97 has an OBDII cat which has the o2 sensor built-in. Pre-OBDII (OBDI) cats do not have the o2 sensor built-in, I am not sure if those vehicles even have the 2nd o2 sensor. I don't know why it is put there but since it comes that way, I would keep it that way.

X2 For going ahead and getting a new cat

When I was looking http://www.discountcatalyticconverters.com had some of the best prices.

 

My 97 had the o2 built into the cat and when I replaced the Cat with a magnaflow aftermarket one it was set up the same way. The o2 is on the exit side of the cat built into it. My buddies 99 was the same way.

 

so i have to get a new cat with the o2 built in?

 

i was browsing and found this