Catalytic Converter Which one for Ca SMOG?

[born2shift]

I just got a 1991 Q45. It is not passing SMOG. Everything is clean except the Nox which is a little high. I think the cats are gone. There are four that I know of. Should I get an aftermarket Magnaflow high flow cat or just stick with OEM?

[BUZZlightyear4]

Buying new cats is going to cost a LOT of money. Considering it is a 91, you probably won't find buying OE parts worth the money.
About Magnaflow..."high flow" cats don't really exist. In California, cats uphold a high emission standard. Worry about getting your CEL off and passing SMOG, not high flow.
Magnaflow makes decent parts. Catco I like better, even though they don't have the brand name that Magnaflow does. Cheaper also.
Call or email the guys at http://www.californialegalconverters.com. They're a big help and know their stuff