Just get some quotes from local car repair shop..It costs at least 150 to drill a hole on stock DP and weld the bung onto it.. The price is crazy but I don't have welding machine so it could only be done in shops. Just want how much did it cost you guys to install it. Or should I just get a DP with bung for WBO on it? Thanks!

 

I'd say $25 is fair if you bring in the downpipe & bung. I say ditch the stock dp though and get a 3" replacement that already has a spare o2 bung.

 

Thanks for the reply! I think I would just get an aftermarket DP.