97PearlWhiteSe

I recently had to change the knock sensor a few weeks ago, and a bad o2 sensor a month b4 that. Now my catalytic converter is bad too. Is it because my other two sensors went bad?

DAVE Sz

iTrader: (2)

Most likely. If the car runs rich it will ruin the honey comb inside the CAT. I read that someone went through 2 new CATs within a month cause his car was running rich, or was it lean?

Midknight MAXX

iTrader: (1)

I'm pretty sure it's rich. I found THIS LINK on HowStuffWorks.Com. The O2 sensors control air fuel mixture so that could be it. The knock sensor controls timing I believe, so I don't know if that will affect the cat.

njmodi

iTrader: (4)

As Big D stated - if the O2 sensors are not working correctly, too much unburnt fuel (i.e. too RICH a mixture) makes it through the exhause/catalytic converter - clogging the honeycomb... Did you wait a long time after the O2 sensor CEL was reported to replace it?

97PearlWhiteSe

The rear 02 sensor went bad, and I waited about a month to replace it.

DAVE Sz

iTrader: (2)

The rear o2 sensor WON'T do that. One of the fron ones is bad but not bad enough to cause a CEL.

97PearlWhiteSe

The o2 sensor I was talking about is the rear bank o2 sensor which is in the y-pipe. If that sensor goes out would that cause the cat to fail?

DAVE Sz

iTrader: (2)

That's the FRONT RIGHT O2 sensor and yes, yes it would.