California Legal manifold/headers

So we have a 2001 Taco, 3RZ 2.7l automatic that started its life on the east coast. We changed the timing chain to clean up a peaky p0340 code and now engine runs great but went to smog it and it has some full length exhaust headers (unbranded) that don't have any numbers for the smog guy. Looked into just ordering some legal full length headers and LCE and Trailblazers come up but both say carb legal up to 1999. The truck has one single CAT under it and no engine codes so I'm guessing the truck only came with one cat originally. I can find stock exhaust manifold lots of places but the intermediate pipe where O2 sensor goes and connects to Cat section all come with another Catalytic convertor in them for big money. Would the LCE or Trailblazer work and be legal because the truck maybe didn't come with 2 cats originally or do I need a 2nd CAT and run stock manifold? We are at a loss right now. Have 90 days to get it sorted or have to pay for retest