Missin O2 sensors?

NKTIDWEL

MEMBER
FORD MUSTANG

I have a 1998 Mustang with the 3.8, but with a true dual exhaust. I bought this car used. I am unable to locate the O2 sensors on the exhaust manifolds. I found the two after the Cats, one for each pipe. I have looked a few times. Is it possible that the exhaut manifold has none?

Saturday, April 14th, 2007 AT 5:28 PM

3 Replies

TAURUSWHEEL

MECHANIC
718 POSTS

Are you sure the two downstream are not catalyst monitors. According to my book, the 3.8 has two o2 sensors located below the exhaust manifold in the dual converter Y pipe below the exhaust manifold while the catalyst monitors are located downstream from the cats.

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Saturday, April 14th, 2007 AT 11:29 PM

TAURUSWHEEL

MECHANIC
718 POSTS

I re=read your question again, is your check engine light on? So someone modified the factory exhaust system, didn't that car come with one muffler originally? With two tailpipes? It now has two cats and two mufflers?

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Sunday, April 15th, 2007 AT 9:01 AM

NKTIDWEL

MEMBER
7 POSTS

There isn't a Y pipe. It seems to be a true dual exhaust. There are the headers, then pipes to the cats. The two downstream could very well be catalyst monitors. But then I could not locate the O2 sensors. The person who owned it before me put in a custom exhaust, and did other things to the car, that I have yet to figure out.

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Sunday, April 15th, 2007 AT 9:05 AM