there are two different size catalitic converters for US model 348's. Part #134001 and #134002. Which side does the larger one go on? i'm trying to trouble shoot a resonnance I'm getting at certain RPM's ever since the cats were put back (Car had test pipes previously), and before I take the whole thing apart to just check the status of the cats I want to verify that they are each ontheir corresponding side. thanks, vincent.