I was reading the 5th gen FAQs and came across this statement:
"First of all, if you have a 2001 Maxima, it has California/NLEV Spec emissions."
I don't understand why Nissan would make every 2K1 Max a Cali Spec?

 

Yes, it's cheaper to make ONE car then two versions.

Pretty much all new cars are coming 50-state legal and if they pass Calis' strict emissions, they'll pass anywhere.

 

So are the 2Ks faster than the 2K1s due the stricter exhaust sytems?

Could you buy an aftermarket Y and gain a lot of power from it? Would there be problems with the O2 sensors?

 

SUPPOSEDLY the FED spec 2Ks have 10lb-ft of torque more then a 2K/2K1 Cali spec..

However, a few 2K1s(Cali) have converted to FED spec. and the gains were minimal. Check the How-To stickies for DesertPearl.

Anyways, FED+Ypipe = no precats, but CALI+Ypipe = 1 precat. You don't have any issues with 02s on either and a Ypipe.

If you convert a Cali->Fed, you need to relocate the rear 02s though.