Okay so i was just drivin along and my check engine light poped up the first time ever. So i went to good old advanced auto parts to use the code reader. It came up as catalist effiency blow threashhold. Exactly what does that mean in mechanical terms in other words.

 

Change ur catalytic converter

 

Sounds like the cat.

 

It could be the CAT or the 02 Sensor???



Modified by r3v da t3g at 6:52 PM 10/16/2006

 

The cat is new like june new its a magna flow hi flow

 

What year is your car, 98 i presume? Which is OBD2 and has two o2 sensors. One that records oxygen content before the cat and one after and sees the difference, that way if the cat is bad or plugged it will know and CEL will come on.

CEL are emissions related only so something is causing the ECU to think something is wrong. A high flow which doesnt cause as much of a chemical reaction as a stock one could very well set a CEL.

How long has the light been on? Since you bought the cat?

 

the cats been on since june but the light just came on sunday the 15th of this month so a couple days ago

 

OBD2 cars have systems that check themselves for DTC's (diagnostic trouble codes) if you perform the right criteria while driving called a trip. You might have ran that monitor and your o2's didnt pass the self test because of the cat. Do you have the stock cat you could swap back in and have the codes cleared, or have the monitor retested?

 

I have a hi-flow cat.