PartsAvatar.ca Provides Muffler and Pipe Assembly parts made by various manufacturers. A complete internal drainage system helps prevent condensate acids from collecting between partitions or at the muffler heads. The section of tubing between the catalytic converter(s) and the rear muffler on cars that have two parallel exhaust pipes. Performance mid-pipes often have a perpendicular connecting pipe or the pipes temporarily merge. This is to equalise the pressure in both exhaust pipes.