Catalyst below threshold fault

[henryg]

Hello,

I keep getting the same fault popping up telling me the catalyst is below its threshold. I have a Piper turbo back exhaust system with a sports cat fitted. When I fitted the exhaust 8 months ago it was fine up until now.

Any ideas on what it might be?

Cheers,

Henry

 

[ibizatom]

Over fueling?

 

[JamJay]

Is this your fault?

16804 - Catalyst System: Bank 1: Efficiency Below Threshold

If so, it's due to the Sports-Cat. The car thinks that your OE Cats are broken as they're flowing too much, obviously it doesn't know that it's meant to. Are you Stage 2 Remapped? If you are, then the mapper should have adjusted the expected values for emissions and exhaust flow to allow for it.

I suggest you look for a lambda sensor spacer on Ebay so that the car cannot detect the fault.

 

[JamJay]

By the way, the above fault code is for the post-Cat lambda probe, if yours is different then it may the the pre-Cat sensor at fault which most likelty means that it's faulty.

 

[henryg]

cheers mate... when I get home I will stick the VAG COM on it and check the exact fault.

It is at stage 2ish.... just waiting to go hybrid.

 

[henryg]

Is this your fault?

16804 - Catalyst System: Bank 1: Efficiency Below Threshold

If so, it's due to the Sports-Cat. The car thinks that your OE Cats are broken as they're flowing too much, obviously it doesn't know that it's meant to. Are you Stage 2 Remapped? If you are, then the mapper should have adjusted the expected values for emissions and exhaust flow to allow for it.

I suggest you look for a lambda sensor spacer on Ebay so that the car cannot detect the fault.

So if it is the post cat sensor and I get a spacer for it. What happens .... I dont anymore faults because the sensor has been removed do I?

Thanks,

Henry

 

[JamJay]

All the spacer does is move the probe further away from the exhaust flow. The sensor will still detect exhaust flow but not as much as it does now while it's sticking directly into the Cat. This will put your engine management light out and clear the fault from the ECU, no more faults will appear as a result and most certainly there will be no change in the car's performance.