emmisions light on code 16804

[KevM3]

16804
Cat system, bank 1
Efficiency below threshold

P0420-002 lower limit exceeded-intermittent


ilight came on the other day , i cleared the codes then came back on 2 days later when i floored it,
any common faults on that lot above , thanks

 

[Dan TheMan Welburn]

That fault code description would make me think there is a fault with a lambda sensor

 

[moggie93]

Taken from Ross tech website

16804/P0420/001056 - Ross-Tech Wiki

hth m

 

[KevM3]

smells like ive got a slight exhaust leak under the bonnet , that old smell of pre-cat cars exhaust , so there must be a very small leak from a recirc pipe somewhere i reckon,or the down pipe before the cat

 

[KevM3]

ive got a broken breather pipe, the elbow one on the oil filter housing,this will be the fumes im smelling,crakcase fumes, havnt fitted it yet but wondering how it will affect the emissions and throw up them codes

 

[KevM3]

fitted the breather and the light still comes on after clearing the codes, cat will pass an mot as ive had the emissions checked, i cant do a full vcds check as i got restricted access on mine , anyone in the cardiff area got a full vcds system?