getfocusworking Posted February 19, 2009 Share Posted February 19, 2009 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 PO420 and this reads to the book as 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. Quote Link to comment Share on other sites More sharing options...
SierraYankee99 Posted February 19, 2009 Share Posted February 19, 2009 Possibly a lamda sensor going down?? Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Ford UK Shop
Sponsored Ad
Name: eBay
Ford Model: FordUK Shop
Ford Year: 2024
Latest Deals
Ford UK Shop for genuine Ford parts & accessoriesDisclaimer: As the club is an eBay Partner, The club may be compensated if you make a purchase via the club
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.