Audi A3 engine management light issue help needed

bengalknights

Use scrap parts from local yard,

Any Golf, Leon or Octavia cat should work on the A3

colino

Go to a proper independent. If your car is running well and is not drinking fuel it most certainly doesn't have a blockage in the cat (there isn't a bypass) and it's dubious if the MAF is out too. You'll end up throwing expensive parts at this if you keep on getting dodgy diagnosis.

wookie66

They were reputable independent Audi specialists since got their contact from the audi forum website + they have been nominated / won number of awards. They are based in Kingsbury and i dont have any incentive to plug them so my opinion is not biased towards them. However I appreciate that this could end up with me chucking good money after bad ie replacing the MAF and Cat may still not resolve the issue!!

vaio

I'm inclined to agree with Colino, if the cat was blocked then the car either wouldn't run at all or would run like a slug.

If performance and fuel use are normal I'd be inclined to ignore the problem until you have a real problem to deal with.

At the moment you seem to be trying to cure a light on the dash and have spent £250 and still have the light. Lambda sensors, MAF & CAT are the standard easy & profitable "throw parts at it" options for garages.

I would be tempted to run round the engine bay unplugging every connector you can see and reseating them as well as checking they aren't corroded, this will often cure intermittent faults/sensor issues like you seem to be experiencing.

wookie66

Sound advice Vaio and agree that one shouldnt take all recommendations made by garages as the only option

I will probably run the car until there are any performance issues or it fails its MOT on the emissions test (due April13) before parting with any more dough

As much as I love my car when these electrical type faults occur you do wonder why they make them so difficult to pinpoint and resolve

The cynical part of me says its just plain economics and that they (car manufacturers) have to recover their R&D costs + overheads from you and I

Appreciate the advice provided so far

Horizon81

You know what I'd do. Nothing.

The car drives fine. As long as it passes an MOT emissions test then you're legal. Colino is spot on that P0420 is a money pit. You could replace all the parts you list and still have the same code. On my friends Toyota that light came on a few months after the cat was changed. I personally spoke to Toyota and they advise that as the cat wasn't a genuine one it could run to slightly different tolerances which are outside of those that the ECU is set up to. So you would always get the fault code, even though there's really no fault

Given the age of your car, I'd just drive it and ignore it.