Does the Dp replace all the way to the cat back and doe sit bolt up to the greddy evo, also how is the fit and finish quality of the up pipe is it prone to leaks and such as well as the EGT bung leaking any info will help greatly?

 

so I take it the gruppe s uppipe is good quality then.what bout the o2 sensor bung on it i have heard that if A uppipe has one and u can't the sensor back in correctly it will leak? What can be done bout this?