S3 revving on idle also slight misfire

[LukeB90]

Hi guys,
Recently encountered a problem whilst the car is on idle it has started to rev when ticking over with a bit of a misfire. The car when driving is absolutely fine and still pulls well etc. The problem is worse when the car is warm. The car is also automatic (if that makes any difference) my mate plugged in a diagnostic computer and it came up with these codes any ideas?
00768| Random multiple cylinder misfire detected P0300 not a plausible signal
00772| Cylinder 4 misfire detected P0304 not a plausible signal
00770| Cylinder 2 misfire detected P0302 not a plausible signal
08825| Leak in air intake system P2279 lower limit reached
04243| Bank 1 fuel measuring system 2:malfunction P1093 not a plausible signal
It also smells a bit rich but that might just be me imagining things. Do you think a leak in the induction could be the main culprit?
Cheers guys any help would be appreciated.

 

[LukeB90]

Anybody have any ideas? Cheers

 

[Charlie23]

Could be a few things really mate.

Have you checked all the common things, like Coil Packs, Plugs, PCV Valve, Maf Sensor?

 

[LukeB90]

I've swapped plugs and could seem fine still happening in changing PCV valve now and I hope that will cure the problem

 

[LukeB90]

A new PCV valve sorted it when I swapped the plugs though the old pugs were very light grey almost whiteish does this mean it's running lean? Or could it of been a result of the PCVvalve been on its way out and affecting the fuel air ratio?

 

[Jnsio]

A new PCV valve sorted it when I swapped the plugs though the old pugs were very light grey almost whiteish does this mean it's running lean? Or could it of been a result of the PCVvalve been on its way out and affecting the fuel air ratio?

That is caused by the PCV valve. I just had to replace mine last week and as I checked my 2 of my plugs were also pretty clean/gray ish. Checked again a few days ago and now they are back to normal.

 

[LukeB90]

Thanks for the heads up