The engine dies about 50% of the time when I engage the clutch upon braking

What is your question?

I have had the engine tuned up and new filters replaced. I also have a constant engine warning light that my mechanic cannot find the reason for with his electronic equipment. Some times I can drive and I experience no engine failures and other days, the engine fails each time I brake. No rhyme or reason with the outside temp, as it is erratic in both cold and hot days.