Please help new faults

[acano]

Hi all, left the house and the car started misfiring.
stuck it on VCDS which threw up these codes:

4 Faults Found:

16804 - Catalyst System: Bank 1: Efficiency Below Threshold

P0420 -- 001 -- Upper Limit Exceeded

17771 - Cylinder 3 Ignition Circuit: Short Circuit to Ground

P1363 -- 001 -- Upper Limit Exceeded

16697 - Misfire(s) Detected: Reason: Lack of Fuel

P0313 -- 001 -- Upper Limit Exceeded

16691 - Cylinder 7 Misfire Detected

P0307 -- 001 -- Upper Limit Exceeded


I know what the problem is with the first one (o2 sensor) but what about the rest?

thanks Tony

A4 2.0 SE 2001

[Crasher]

What is your engine code?

How can you have cylinder 7 misfire on a 4-cylinder car?

[acano]

What is your engine code?

How can you have cylinder 7 misfire on a 4-cylinder car?

where would I find the engine code?
and I have no idea why cylinder 7 on a 4 cylinder car

however I have cleared all the codes and although not as responsive, it does run without the Engine management light flashing and isn't misfiring or not that I can tell?

thanks Tony

[a8 tech]

if the misfire counter is haywire (random cylinders and counting up very quickly) then check fuel pressure and check the cats for partial collapse.
Remove a lambda probe that's accessible and see if there is any greyish powder in the exhaust