I wanted to know if you can remove your airpump and leave the stock cat on the car or do you have to change to a high flow cat? With the high flow cat and no air pump can you still pass emissions in California?

 

nope... you need the airpump to pass smog...

 

Most hi-flow's that are designed for the FD are made to work with the air pump. Unless you really need the extra space in the engine bay, leave the air pump in place, especailly in CA.

And no, without the air pump, you will not pass the smog test.

 

you can always rig up an electric air pump setup and switch the hi flow on and off... thats how I passed