Is it better to run hotter during emission testing?

[d0n_3d]

My car normally runs at 160 with the fan on high all the time...should I keep my fan off and have the temps around 200 degrees when testing? Or should I keep the fan on...

 

[gofstbuick]

Since you barely passed NOx with a gutted cat, chances are, the NOx numbers may increase when the engine is heated. Does the test require your vehicle to be tested at 30mph? At a steady state or does it test as the vehicle is being accelerated? What is happening to the rest of the emission readings?

 

[Danster]

Run it hot!I had mine around 200 when it went through the sniffer.


Dannyo

 

[Captain Duckman]

Most newer cars are programmed from the factory to run hotter because of emissions....from what I've heard, its usually better to let your car run hot during testing.