Sorry for asking just wanted to know what the difference is with the downpipes with and without the flex area...

 

the flex is so that the entire downpipe doesn't move around under engine torque and vibration. apparently it's not too necessary because of a certain gromet like gasket donut thing that is on the o2 housing that most of the aftermarketers are deciding to reuse. if you get an 02 elim downpipe it's prolly crucial to have the flex. but it doesn't hurt to have it anyway. it's pretty important to not have the dp move around because it's close to the tie bars and oil pan and such which isn't healthy for the parts it will rub nor is it comfortable to have the vibrations transfered to you when driving.

 

okay great sounds Good thanks finally a reply on this thing...

 

either you use flex and solid bolts to your o2 housing,or those spring bolts and the donut ring w/out flex
i personally IMO would get the flex section if the company you wish to use has that option because the spring bolt /solid tube combo. has a tendency to crack if the flanges on the DP are not thick/larger guage material,becaus the entire weight(hanging-) of the exhaust is on the flange and spring bolts creating unnessesary stress ,where w/ a flex that weight is roken up/distributed under torque