Fault Code - 16804/P0420/001056 - Catalyst System

Matt S!

ovni ibiza cupra 1.8T
Apr 9, 2007
208
0
stoke-on-trent
Hi peeps

Ive got the below fault on my Ibiza Cupra 2002 (ayp)

Any of you had this before?

My car drives ok and boosts as normal but the CEL light comes on now and then

I have a Blue Flame full exhaust system

16804/P0420/001056 - Catalyst System; Bank 1: Efficiency Below Threshold
Possible Causes
Oxygen Sensor(s) defective
Oxygen Sensor(s) Control defective
Possible Solutions
Check Oxygen Sensor(s)
Check Oxygen Sensor(s) Control
Perform Oxygen Sensor(s) Aging Check
Special Notes
For 1.8T's experiencing this fault code, this thread may be useful: http://forums.vwvortex.com/zerothread?id=663057

The vortex thread states it may be a leak from the cat or a dodgy sensor

Any ideas?

Thanks

Matt
 

RichN

Collecting Rings
Jan 29, 2005
533
0
Oxford
www.Oxford7s.net
Just ideas...

How old is the BF 'system' - i.e. 100 cell cat, or the newer 200 cell? Often the 100 cell cat's require the lambda sensor to be spacer'd back a bit.. ever tried to pass an MOT with your current setup?
 

Matt S!

ovni ibiza cupra 1.8T
Apr 9, 2007
208
0
stoke-on-trent
Yeah - fixed this when I had it serviced

Turned out to be a perished vacuum hose! They fitted new hose and it was fine...
 
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