[Sandy42]

Hi, I use Torque Pro w obd2 adaptor to monitor stuff. My 1.4 cat temps range from 900s to high 1500s and are constantly changing depending on the driving condition. I've been using TP for at least 2 years.
I searched and this article seems to explain in techy terms:

Oxygen Sensor: Catalyst Efficiency

The catalyst efficiency monitor verifies that the catalytic converter is operating at a high enough efficiency rating to keep exhaust emissions within predetermined values. The PCM compares the signals from the upstream and downstream oxygen sensors to determine the state of the converter. These...

www.underhoodservice.com

Thanks a lot!
Have you observed your cat also glow orange in night after driving on highway? A little background my old cat(99k done) brunt down without any warning on a 5 hr drive, that was glowing red in night before failing. I tried to find out the root cause, took car to multiple mechanics as well but no success(no check engine light other then p420 before cat got burnt). Yesterday took car to dealership, only thing they can think off may be second cat has some restriction that causing high temp and making first cat glow orange when driving on highway. Any thoughts?

 

[Sandy42]

Thanks for sharing your thoughts, car had been inspected for all engine related issues like lean, rich, misfire etc after installing new cat nothing find out neither by independent shop nor by dealer and also never had check engine light. That is why confuse about this situation.

 

[Sandy42]

The max allowable cat temp is 950C (1742F). 1350F is a perfectly normal operating temperature.

Thanks for the information.

 

[Sandy42]

Car is all factory no tune etc, old cat was GM only and new one also GM original, I saw both of cat old and new one glowing so know the difference now. I am also concerned about how old cat burnt down without any warning, initially I thought because my ignition coil connector got loose and caused misfire on the long drive that was the reason but only once engine got completely dead while driving check engine light came on, I opened the hood cat was red, put the ignition coil connector back on and car was running fine but dont you think continuous misfire should happen in order to burn the cat completely and in this case check engine light should come first before cat burn down. today I looked inside of my cat and turbo with borescope cat is still white like new. Yes worry point is why it is glowing in night after just one hr highway drive, not sure it is normal behavior or not. Dealership mechanic just mentioned as a possiblity that may be second cat is restricted and creating back pressure.

 

[Sandy42]

Just want to update with some more information: took car on highway and monitor CAT temp in city it was ranging between 1400F to 1600F on max speed 55 MPH but on highway when accelerating towards 80 MPH Temp reached 1700F and stay between 1650F - 1700F on speed between 75MPH - 80MPH on a period of 15 minute. Under the max range 950C (1742F) given by chilehed. Still my range is more towards max limit.