Ok the basics first:
2000 - PreRunner XtraCab - 2.7 liter - Automatic - 2wd.
So after months of attempts going from CEL code directing front cat, then back, then front, then back again and so on... also after replacing both front and back O2 sensors with no positive results to keep CEL off. The mechanic at the dealership ended up putting a 3rd Cat. Conv. inline between front and back cats. Now totalling 3 Cat. Conv.
So first off, Im sure this is not even legal state smog regulation wise. Secondly, Im sure this mechanic isnt one Im going to run and recommend to family and friends with Mickey Mouse fixes like these even if he did eventually get it the CEL off.
But what exactly is going to be the downfall, the negative factor in adding an additional Cat to my truck? Will performance suffer, will MPG's go down, will it have a tendency to overheat now, any other components going to get severly affected? What do you guys think/know?
PS: If relevant, im in California state.