Please read my referenced threads, which explain how NOx is created. It is created in the flame front at 4500 degrees F and has nothing to do with engine coolant temperature.

Retarding timing reduces peak combustion temperature and significantly reduces NOx even though it increases coolant temperature due to the higher EGT transfering heat to the cooling system as the exhaust gas traverses the exhaust port. How do you think my car's NOx measured low double digits?
Also, high EGT keeps the converter hotter.

Some people here need to read the emissions information I posted and reference on this forum to learn what's going on and quit posting myths, misinformation, and amateur theories!

I did graduate research in IC engine emissions generation and control at the U. of Wisconsin Engine Reserach Center, and I understand the subject at a low level of detail.

If anyone has better credentials than this, I, and I'm sure others, would like to hear what they are.



Duke