Can a newly replaced catalytic converter cause a failure with a vehicles O2 sensor?

Question

I just recently had my catalytic converter changed and less then a week after it was replaced the check engine light went on in my 1996 Honda Accord. I brought the car back to the mechanic and they told me that the 02 sensors need to be replaced. I was wondering if it is likely that the 02 sensors failed because of their faulty work in the replacement of the CAT, or is it more likely that the CAT needed to be replaced because the O2 sensors were bad?
Also does anyone have any idea what it should cost to replace the O2 sensors on a 96 Honda Accord?
Thanks in advance for any advice you can provide

Answer 1

O2 sensors tend to go bad at that age. I wouldn't bother with OEM sensors on that car. Just use the $40 generics from Autozone.

Answer 2

A cat converter usually fails because of a poor air/fuel mixture. The converter is designed to burn off any unburned fuel. It does that by running the exhaust into a 1,500-2000 degree converter. But if you have excess fuel, the metals inside the converter that react with the unburned gas heat up even more--sometimes over 2,500 degrees. At that point the metals start to melt and destroy the converter.

A bad O2 sensor or some other air fuel problem is usually the CAUSE of a cat failing.

Rick

I'm a retired ASE Master/L-1 Technician. I still keep current with the latest automotive technology. Visit my blog for cool articles and TSB's: http://free-auto-repair-advice.blogspot.com

Answer 3

Oxygen sensors go out quite often. Replacing them is no big deal, some just screw in like a spark plug others are held in by a couple bolts.

An OEM sensor for your car shouldn't cost more than 80 dollars, an aftermarket one around 50 dollars. You can get one at any good auto parts store.

Answer 4

would have been the perfect time to replace the sensor(s)

Answer 5

It was time for them to go.