I bought a Walker exhaust (cat back) for my 94, v6, 4wd. It looks fine, except the middle pipe, forward of the muffler, that connects to the cat, seems shorter than what is there, and does not have a connection for what appears to be a second O2 sensor.

The engine compartment label says it is a non California model. None of the after market muffler people seem to carry a California model. And none of them show this extra connector.

There is another O2 sensor (I presume) ahead of the CAT. Would it be safe to remove just ignore the second O2 sensor and disconnect it?

Where can I look for more information?

joe a.

 

It would probably not be a good idea to leave an O2 sensor disconnected. An exhaust shop can weld an O2 sensor bung on for you and it should not cost very much.

 

Thanks. I do not trust the only brand name shop around here. I guess I could shop around.

I can weld and would give it a go, myself, if I could find the fittings. I have googled a bit and not found a Toyota style "flange" to weld on. I find round, threaded, "bungs" everywhere. Which, I suppose, I could use, but that requires I put in a new O2 sensor.

BTW, do people generally change CAT's if they appear to be working? This truck as about 160k on it. The cat is somewhat rusty, but appears in good condition, otherwise.

 

Actually, as I look at pictures of the flange style sensor, it appears the flange may simply be "screwed on" to the O2 sensor. I may take a trip to the local auto supply house later, to be sure. If that is the case, a simple weld on bung (screw in type mount) may be all I need, just spacing it so the sensor sits about where it should, in the exhaust stream. If I'm lucky I might even be able to save the old one.

Comments?

 

Taking off the old one would be easy. I bought a screw in type bung at the local muffler shop, but I do not think they had the other style. Unless you are having problems with smog or if your cat is clogged, then you do not need to change the cat. There is not really any good way to test it, but it should get really hot if it is working.

 

I also had Walker Exhaust replacement but didn?t had that kind of problem. But, this info would help a lot.

 

Further conversation with Walker tech support indicates they do not make this style, which is a "california" emissions unit. Did you do the work yourself, or did a shop do it? And maybe not mention any welding?

Funny thing is, my truck is clearly marked "federal and canada" and not for california, yet it is a california emissions model.

I ended up calling the dealer and was astonished at how reasonable the unit was, not too much more that the walker unit, without the flange. And, it was in stock. So they must run into this issue a lot.

If I had to do it again, I'd get the front hanger, where the cat and muffler pipe meet, and the rear hooks and the gaskets, from walker, as those are about half the dealer price.

I must admit tho, that the dealer items are quite substantial looking and fit perfectly. And were on the shelf.


joe a.

 

I bought that style stainless bung on ebay, thinking I would do that, but ended up finding out the dealer had the proper muffler in stock, for about the same price as the walker (street price).