i just ordered a pipe to replace the main cat do i just bolt it up or is there some air pump thing that will keep the 5th and 6th ports from opening?

there is a 3 way valve for garden hoses(found at walmart or other hardware stores) that i used there is a write up somewhere,

sorry that probaly didnt help alot though. but i like it.They are other ways though.

W/ solenoids. good luck. https://www.nopistons.com/forums/pub...IR#>/smile.png

[quote name='joker90p' date='Aug 22 2005, 07:57 PM']i just ordered a pipe to replace the main cat do i just bolt it up or is there some air pump thing that will keep the 5th and 6th ports from opening?


[/quote]



Looks like you have a '90 model year (S5). S5s don't use back pressure to open the aux. ports, rather the stock air pump. So the pipe shouldn't affect the aux. ports.

thanks guys