so change to aftermarket exhaust can help?? 
Yes, yes yes, modify it to double big exhaust could help...like you
see WRX, outlet so fast, engine gets clear of exhaust in time,
efficiency up, and yet effective in power.
Sonata, knn, heavy, yet the exhaust is like a 1.4cc with a lousy
catalyst, you expect with turbo pick up, the exhaust will go off
fast, I do not thing so, before the exhaust heat is clear, the next
explosion happen, therefore, timing wrong, exhaust wrong, leading
to sudden heat up, private sonata with petrol driven do not have
turbo, and it is because of turbo, some accidents happened
