I'm looking to take test pipe off and go back to a catalytic. But I need to find a replacement. I would like to get a Hi Flo cat but I'm not sure it will pass smog.

Has anyone gone with a hi flo cat and passed smog test/inspection?

 

Any cat that is in good working order will effectively reduce hydrocarbons.

 

I think I read somewhere that the stock cat is a high flow cat to start with. Or did I read wrong?

 

Nope, you read it right. OEM cat is hi-flow.

 

I changed to a Random Tech hi flow and inspection readings (granted they were a couple of years apart) were almost identical

 

your stock cat is hi flow, so if you still have that just put that back on