Jun 29, 2001
536
0
Surrey
Hi guys,

Just wondering if someone can confirm that I'm on the right track here.

Keep getting fault code 16804: catalyst system below threshold and the engine light comes on each time I clear the code.

Now, from the information I've gathered from a search, it's either........

a) Dodgy oxygen sensor.
I've replaced both of these recently. I did the post cat sensor at the back
end of last year and the pre cat sensor was replaced last night, so I'm ruling
these out.

b) Knackered cat.
What's the symptons of this? Is there any loss of perfomance when this
happens? The car still flies so I'm unsure if this is the problem.

c) Possible leak from joins on exhaust.
This is something I'm going to check and make sure all clamps are tight.
Would even a small leak be audible? Any other side effects from this?

d) Use a spacer on the post cat sensor.
Anyone know where to find one of these?

Is there anything else I may have missed that could be causing this?

Sorry for all the questions but this is something that's been going on for the last 2 years (yes 2 years) and cost me a small fortune in the process. Lots of stuff has been replaced like MAF sensor, oxygen sensors, coilpacks, sparkplugs etc etc (all done this year). All vaccuum piping has been replaced with silicon pipework and is leak free.
The car is a Jabba mapped Ibiza with K03S, 3"dp with 100cel cat bought from AM Motorsport.
 
Aren't any of you lot getting this fault code then with your sports cat's?
Surely I can't be the only one. My mum always told me I was special.
 
same problem

if got de cat and im getting the same problem ,ive heard something about bridging the gap on the sensor so that it doesnt read soo much of the air passing through but carnt find out how much u need to gap it by . have u sorted the problem yet m8t
 
With a decat, the only way I know of getting rid of the code is by getting the post cat sensor mapped out. I've read about wayne angle blocks as well but I'm not sure if this'll work with a decat.
I never actually resolved the issue, it kind of resolved itself somehow. I no longer get the code any more and haven't done for some time.