Racing engines with wide overlap cams and open, tuned, exhaust systems can indeed create a negative pressure pulse at the exhaust port…But mundane Nissan passenger vehicles have no means to “suck sand back into the engine”…The flow out the exhaust in today’s smog engines is one way…Also, if Cats were breaking down and somehow pumping grit back into the engine, other makes and models would be affected as these components are manufactured by companies that supply more than one manufacturer…2002- 2005 models are considered museum relics by the manufacturer… warranty commitment long expired…They view the products they make as disposable consumer products, like washing machines… You should view them that way too…You should also consider that MILLIONS of Nissan owners do NOT have high oil consumption problems and are very happy with their vehicles…
If Nissan dealers had been provided with the means to reprogram the OBD-2 government mandated emissions system so it would ignore CAT failure, this fact would soon be discovered by federally mandated emissions tests which would discover that the actual tail-pipe emissions were way over the allowable limit but the OBD-2 system failed to detect or register that fault. The Government (EPA) would be VERY unhappy at this fraud and Nissan would be in serious trouble, looking at a sales ban and tremendous negative publicity…
If you feel Datsun has treated you unfairly, your only recourse is to never buy another vehicle from them…