360 (need help!) 360 Modena not "Emission READY" for Smog Check & CEL: P0431 code

I am in California.

My 2003 360 not "Emission READY" for Smog Check & throws CEL for P0431 [reads: generic, Warm Up Catalyst Efficiency Below Threshold (Bank 1)] code on OBD II Scanner.

I have Factory pre-cat (inside honeycomb removed) & Factory catalytic converter.
___________________________________________________________________________________
CEL usually comes out every 40~60 miles during normal driving. So I've did the following:

1. Drive the car extremely slow (low RPM on local street and mostly 60mph in 6th gear on highway for 152 miles), CEL come out on the 153rd mile mark.

Cleared to CEL then...

2. Drive the car extremely slow (low RPM on local street and mostly 60mph in 6th gear on highway for 125 miles.

No Check Engine Lights but OBD II still shows Emission NOT READY (Yellow Light)
____________________________________________________________________________________

I would like to know how can I get "GREEN LIGHT" to be Smog Check?

Or do I need to get a new set of Factory Pre-Cat? Or maybe my Factory catalytic converters gone bad?

Or anyone knows if there's any aftermarket Pre-Car or catalytic converter that can pass the California Smog Check?

If anyone knows good smog technician can help me in the LA / OC / SD area, please PM me.

Thank you SOOOOO much in advance for your input.



Image Unavailable, Please Login