Hi,

I own a 1996 Cavalier 2.2

Does anyone know if there should be a sensor tapped in the catalytic converter??

Also, how would the car react if there was a universal catalytic converter installed without the sensor???

Could it throw off a reading of an emissions test???

Thank you,



4CYLS
(Forceless)

it should have a sensor on the drivers side after the cat. if it does not have one, one of two things has happened.

1) the previous owner took off the original cat for anynumber of reasons, didnt put a bung for the sensoron the new cat,and just put an electronic simulator where the sensorshould have been plugged in to.

2) the previous owner removed the old cat for any number of reasons, and just left the rear o2 sensor hanging, or cut it off.

these should throw a code.



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Here's the thing,

I did recently change the catalytic converter for a universal one, but I was totally oblivious that there was a sensor there. (the mechanic obviously didn't inform me about this either)

So now, i have a catalytic converter that's about three weeks old, my car isn't throwing me any codes or my check engine light is not coming on, yet my car just failed it's emissions test today.

The O2 sensor on the manifold has been changed today with an AC Delco one today so that can't be the problem.

Any help would be appreciated.




4CYLS
(Forceless)

No codes may have popped up, HOWEVER your computer is how they test cars for emissions nowadays, no more probe up the tailpipe. Tester found no signal coming from non-existant O2 sensor, so there was no way to know if the CAT was working. Easy fix, sorta. You need to have someone drill a hole in the outlet pipe of the CAT, then have an O2 sensor bung (a nut basically) welded on over the hole. Screw in the 'special' after-CAT sensor and you're now fully legal again.

so most likely, the sensor wire was cut-off then (like rich Grayo said) and there should be an existing wire somewhere?

It it posible to splice into that cut-off wire to connect the sensor then?



4CYLS
(Forceless)

Yeah, well, kinda. The wire is (was?) long, and ran along the exhaust tucked behind a shield, then up into the engine bay plugged into a socket in a wire bundle I think. If you're missing the conector at the end of that wire, best to get a new one, or salvage one off a junker. The rear O2 is a 'heated' one which either/or gets up to 500+ degrees F by itself/ exhaust gasses.

You guys need more experience before spreading wrong info. not ALL 96+ had a sensor after the cat. I've seen 2 97 Z24 FROM THE FACTORY with no after cat sensor. Plain normal. If it would have been removed, there would be a code. It's plain logic. No CEL, no code, emission won't give a damn.



Gilles
2.3 Ho

Mfk-223, I went on the AC Delco parts website and typed in my VIN number and a post converter part came up.
I'm kind of veering in the direction of, if I would have one, my check engine light would come on.
Would there be a fool proof way of finding out for sure though?


4CYLS
(Forceless)

Search for the plug. The number probably came out since it should have it but it doesn't.



Gilles
2.3 Ho

Along the same lines kida, but I have an '02 Eco. I replaced my convertor with a Hi-Flow one 6 months ago, now the car is throwing a code. Catalyst Efficiancy Low. Does this mean I just need a new cat?

Local exhaust shop told me that the Ecos need a "special" cat that actually reduces the air when it comes out the cat, but when I talked to the dealer they said any cat would work, but they woudln't suggest aftermarket. (Duh, they need money too.) Main reason is because of reliability.

95s never came with one hahahahaha

my 97 doesnt have one after the cat. Computer simply shows reference voltage 0.45 all the time.

you don't need it really but if your throwing a code just have a shop put a bung in and run in an 02 sensor. I have mine removed on my 03 and I'm gonna clear it out with hptuners for emissions.


-Chris

I'm glad i don't have to deal with emissions testing.


My car--->http://www.cardomain.com/ride/2569452