Some time ago my Focus 1.6 LX developed a fault.
The amber engine warning light illuminated and my fault reader gave a P04020 error code. My local garage has replaced the cat, the forwardand rear lambda sensors, temperature sensor and the fuel regulator. These were replaced (on fords recomendation) separately but on each occasion the warning light again came on again after about 50 miles. The light is again on now, the error code is the same as on previous occasions but we are running out of options and parts to replace.
The following info came from my memoscan
Fault Code - P04020 Generic Catalyst efficiency Below Threshold (Bank 1)
Freeze Frame info
trouble code - P0420
Fuel SYS1 CL, faulty HO2S
Fuel SYS2 CL, faulty HO2S
calc laod 56%
coolant 112 deg C
ST FTRM 1 -3.1
LT FTRM 1 -6.2
MAP (Kpa) 0
engine RPM 2703
Any help with a diagnosis would be greatly appriciated