would be the PVC hoses on each side, and the air and coolant hoses that need to be removed to take off the plenum. If they haven't been removed in a while they can be very hard and difficult to remove. It's easier and quicker to just cut them off if you have the replacement hose available. Some of the hoses are pre-formed so it's best to get OEM hoses for those. There are schematics showing all the hoses and part numbers in the Pages > docs section of this site. Sites like courtesyparts.com and conceptperformance.com also can have the hoses handy and have schematics. Hope that helps.