You did your exhaust mod but is your engine actually healthy? That is one important factor. Does it consume engine oil or anything?
My interior is strictly all stock except the audio player. I don't want to do anything there, just keeping it as it is.
Engine is healty, no makan minyak. Still can go 17xkmh but take a long distance.
What your temperature bar point after driving certain time. Mine one always near to half, I using double layer radiator