Can anybody help with a fault code that I keep getting about once a month and seems to happen under all types of driving.
The car is a Focus 1.6 Zetec and the year is a 2001.
After seeing the emission warning light come on I check the fault code and it always reads
[b][/b]PO420[b][/b] and this reads to the book as [b][/b]catalyst efficiency below threshold BANK 1
As there seems to be about 20 warning codes that apply to the catalyst can any body tell me what bank 1 means I think it may be the first 4 cylinders as a V8 car would have a bank two ?
There are other warning codes in the book reference the catalyst showing a Bank 2 does
bank 1 and 2 refer to the first and second oxygen sensor before and after the catalyst.
I have checked the whole exhaust pipe and no sign of any leaks were found ?
I reset the warning light and erase the code and nothing happens again until about 100 miles are covered and then on comes the light again.
Hope someone can help.