Alright Peeps,

Recently joined the Audi family and bought a A3 1.8T in Jan . Only had the car for a day and the Engine Management Light popped up, so took it down to my local German specialists to run diagnosis over it.

It came back with the following codes:

16804 - Catalyst System; Bank 1: Efficiency Below Threshold
P0420 - 35-00 --
17705 - Pressure Drop between Turbo and Throttle Valve (check D.V!)
P1297 - 35-00--
18010 - Power Supply Terminal 30: Voltage too low
P1602 - 35-10 - - - Intermittent

The guy at the garage advised me that 17705 was breather hose related and to sort that first and see how it is (he said don't worry about the battery code until I've sorted the other two). Changed the hose which was completed knackered and cleared the codes by disconnecting the battery. Thought I was out of the woods and about 10 days passed and then earlier this week the Engine Light came back! Now I believe the 16804 is the Lambda sensor? I'm presuming it's the pre-cat one due it stating 'Bank 1'? The car lurches a bit when cold and I'm not 100% sure if it's swallowing juice more than it should, as I've not had it long.

Just wanted to see if anyone has had a similar problem or can advise me if they think it sounds like the Lambda? Seems strange to me that it has taken 10 days or so to flag back up? I use the car every day.

Appreciate your thoughts!

Cheers
AL