O2 sensor causing catalytic converter to go bad....how long?
 

2005 Honda Accord 4-cyl., 80,500miles. How long does it take for faulty oxygen sensors to affect the Cat?

I drove for 5-8,000 miles with the faulty oxygen sensor Check Engine Light on. I took it to the mechanic and he told me he'd need to replace the catalytic converter in addition to the oxygen sensors because the cat had burned down....he said he could tell by tapping on it with a pen, and when he tapped, the material inside the Cat was loose.

Obviously its not good in general for the Cat to drive on faulty oxygeny sensors, but in a car as new as a 2005 Honda Accord, how long does it really take driving on bad sensors before the Cat is affected? I need to get this checked out further by another mechanic obviously, but with the oxygen levels reverting to pre-set, default levels, I can't imagine the Cat being seriously damaged after less than 10,000 miles.

How long does it take for faulty oxygen sensors to affect the Cat?

Mine died within a thousand miles or so before.

Excess fuel causes the catalytic converter to overheat and can be damaged quickly. If converter rattles, it's toast.

good luck

OTOH, an O2 sensor that reads kinda correct but sluggish, will probably not kill the cat for a long time. The O2 sensor doesn't have the authority to dump HUGE amounts of extra fuel in there.

Jim Blake--I think the mechanic is trying to pull one over on me. Would he be able to tell just from tapping the cat how loose/damaged the interior of the Cat is? He asked me how long I had been driving with the CEL and I said a few months, so I think I tee'd myself up for the "Well you shouldn't have done that! Now you need an entire new system!" line.



What type of car/age/how many miles did it have when this happened?

What was/is the actual code the PCM is giving?

I Agree With Tex..It's Rattling , It's toast..
 

Oxygen sensor's generally last between 60,000 and 100,000 miles on todays cars.
And like poorman asked, what if any was the code your mechanic was getting on his test.?

WheelBrokerAng :)

Yes, if you tap the converter and it rattles inside, then it needs to be replaced.

The questions remaining...
Did the rattling sound really come from inside or maybe from a loose heatshield? Did you watch him tap it? If he walked into the waiting room & told you this, do you trust him?

Not all mechanics are crooks, not all are angels. It's really hard to tell the difference from over the internet.