Failed emissions

[Larhal]

Question,

What would be the cause of a high Lambda reading, 1.041 Lean condition. CO and HC were passing.

"02 1.8T 156K miles. Fresh Denso Iridium plugs, fresh oil change. Car runs very well but I don't do much high speed driving, village driving mainly. Engine runs strong when pushed.

Any Help would be appreciated.

[Crasher]

The crankcase check valve in the breather system fails but this causes a poor idle so I would suspect a small PCV air leak

[Larhal]

The crankcase check valve in the breather system fails but this causes a poor idle so I would suspect a small PCV air leak

Thank You Crasher,

This is where I was going as I smell a little burning smell in the exhaust, I will revert once I change it.

[Larhal]

The crankcase check valve in the breather system fails but this causes a poor idle so I would suspect a small PCV air leak

Ordered a Audi original PCV part Number 035 103 245 A and a Vent Line 058 103 221 E as that part has nor been reolaced befor.