My header has a crack in it. Is it ok if i still drive wit it?

 

it is fine for a little while depending on where the crack is. If you drive too long on it and too hard you are going to burn exhaust valves ifthe crack is near the head because the reversion of an exhaust stroke and overlap causes fresh air to enter the header and if it is near the head it could cause the valve to heat up excessivly and burn.....or if it is near your o2 sensor you may get a check engine light for the same reason as mentioned before except now the o2 sensor will begin to read lean becasue of the air.... jsut replace it or weld it