FAULT CODE HELP PLEASE

[1wheelonly]

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]

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

• For 1.8T's experiencing this fault code, this thread may be useful: http://forums.vwvortex.com/zerothread?id=663057

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

 

[1wheelonly]

sh*t looks costly!

 

[VRStu]

Are you on an OEM exhaust and if so is it leak free?

If yes then I would suggest 02 sensor changed first.

 

[1wheelonly]

stu
just had a suggestion that the cat might be ******** 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]

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.

 

[1wheelonly]

ive got vagcom

 

[VRStu]

Ahh but do you know what tests to do

 

[1wheelonly]

do i bo**ox.
kinda hoping you did though lol

 

[VRStu]

I'm afraid I don't have a great deal of 1.8T info.

 

[VRStu]

Actually I lie, I have just checked and I have the tests for the 1.8t AUQ.

 

[1wheelonly]

whats auq mate

 

[VRStu]

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.