FAULT CODE HELP PLEASE

1wheelonly

cabriolet
VCDS Map User
not getting any response from the a4 clan so i thought id ask the a3 lot as theres ****** hundreds of you.

My ecu light keeps coming on, reset it a couple of times but it comes back so must have a fault.
here is the fault from my scan, could anyone tell me what it means and what part i need to cure it,also whats involved to fit it.cheers

Address 01: Engine Labels: None
Part No SW: 8E0 909 518 AL HW: 8E0 909 018 A
VIN: 000000000000000 Mileage: 98780km/61379miles
Component: 1.8L R4/5VT 0003
Coding: 0011504
Shop #: WSC 00672
1 Fault Found:
16804 - Catalyst System; Bank 1: Efficiency Below Threshold
P0420 - 002 - Lower Limit Exceeded - Intermittent - MIL ON
Readiness: 0000 0000
 

VRStu

Just Looking
VCDS Map User
http://wiki.ross-tech.com/index.php/16804/P0420/001056

16804/P0420/001056 - Catalyst System; Bank 1: Efficiency Below Threshold

Possible Causes

  • Leakage in Intake and/or Exhaust System
  • Catalyst faulty
  • Oxygen Sensor(s) faulty
  • Oxygen Sensor(s) Control faulty
Possible Solutions

  • Check Intake and Exhaust System for Leaks
  • Check Catalyst
  • Check Oxygen Sensor(s)
  • Check Oxygen Sensor(s) Control
    • Perform Oxygen Sensor(s) Aging Check
Special Notes

Retrieved from "http://wiki.ross-tech.com/index.php/16804/P0420/001056"
 

VRStu

Just Looking
VCDS Map User
Are you on an OEM exhaust and if so is it leak free?

If yes then I would suggest 02 sensor changed first.
 

1wheelonly

cabriolet
VCDS Map User
stu
just had a suggestion that the cat might be buggered but just passed mot, thought they took readings.
not long had new exhaust system OEM but only from cat back, would it need to be leeking before the cat.
 

VRStu

Just Looking
VCDS Map User
I think a leak anywhere from the manifold to the 02 sensor will cause an issue.

There are some tests that can be carried out with VAS/VCDS to test the 02 sensors etc so it might be worth an hours labour if you can't do it yourself.
 

VRStu

Just Looking
VCDS Map User
Ahh but do you know what tests to do :think:
 

VRStu

Just Looking
VCDS Map User
I'm afraid I don't have a great deal of 1.8T info.
 

VRStu

Just Looking
VCDS Map User
Actually I lie, I have just checked and I have the tests for the 1.8t AUQ.
 

VRStu

Just Looking
VCDS Map User
It's a variant of the 1.8t.

I would think the tests would be ok for yours.

PM me an email address and I'll send it over.
 
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