My truck is throwing P0421 code that has been ruled out to the pre cat. My mechanic ( a new guy I took it to) said that any aftermarket cats will probably throw a code again and that I need to go with a OEM cat. The dealer wants 700 and aftermarket cats go for about 250. Any thoughts? Brand suggestions. I can live with CEL light if I can just gewt it pass emmsions. AZ emmisions will fail you with a CEL light on,

edit: I have been looking on line for parts and a confused. Are there two cats up front on the Gen 2.5 a left and a right?

Last edited by OneTime; 03/02/12 06:16 AM.
98 Gen 2.5 w/ winter package & 31x10 BFG ATs.