So Im wondering guys, which exhaust components get clogged besides the catalytic converter and the pre-cats.Mufflers get clogged? Resonators??How can I perform a muffler test if it gets clogged? Are the catalytic converters the only ones with that honey comb interior? Thanks for your time have a nice day!
All mufflers have sound deadening baffles insideBut the converter is the only one with a honeycombCat converters get clogged due to an underlying engine problem that causes them to overheat and melt down, thermal shock (going through a big puddle) or impact damage that cracks the ceramic structureMufflers and resonators only clog when a baffle rusts out and breaks apart You test them with a backpressure gauge.
Polyisocyanurate, also referred to as PIR, is essentially an improvement on polyurethane (PUR)Different catalysts are used and the proportion of methylene diphenyl diisocyanate (MDI) is higher than for PURInstead of a polyether, a polyester derived polyol is used in the reactionThe reaction of polyol and MDI takes place at higher temperatures compared to the reaction temperature for the manufacture of PURAs a result the MDI will also react with itself, producing strong chains of isocyanurateThese crosslinks are stronger than normal bonds in polyurethaneTherefore they are more difficult to breakAs a result PIR foam is chemically and thermally more stable (disintegration starts above 400degC)PIR typically has a MDI/polyol ratio over 400This is defined by an ISO standard: ISO-PIR is typically produced as a foamPIR is used for thermal insulation, one inch of PIR has an R value of 5.30 without any facers[Please read the above thoroughly}
