Haynes manual says, Catylist system efficency below threshold , what does this mean Thanks

 

It could be your catalytic converter or your secondary HO2S sensor. I would replace the sensor first. Most likey thats the problem, good luck!

 

converters have a different warranty than the rest of the car- depending on mileage you may be covered under warranty- see your warranty book or your dealer.

 

Its an aftermarket cat.. we got it with the header and its been installed for a week.. the 2nd Os sensor is in the cat but before the gasses pass throught the cat.. That is why we are getting the code because the computer thinks the cat isnt cleaning the gasses.. Why the hole is before the gasses pass throught i dont know.. the hole was already in the cat when we got it.. and no its not installed backwards.. there is only one way the cat can go on.. where the header meets the cat there are 2 springloaded bolts and where the cat meets the midsection there are 3 bolts.. its a full EX system on a DX




[Modified by CivicGirl114, 3:21 PM 10/7/2001]

 

You MUST have the O2 after the cat- the ecu is looking for a slowly oscillating voltage signal from the second O2- if it sees one similar to the first O2 you will get the catalyst code. The only way to fix this is to have an O2 bung welded in the other end of the cat and relocate the second O2 sensor there.