Hi all I’ve changed my pcv valve yesterday and then started the car and now I have a misfire on 3 of the cylinders and changed the working coil around and it shows up the other 3 still my question is I never had a misfire before I changed the valve so why now ? Or is that just bad luck ? 
 

im looking at changing the coils for the R8 updated coils replace all 4 and also change the plugs too while I’m there 

 

is there anything else to check or maybe even change ? 
 

I have a 2.0tsi octavia vrs 2009 

Edited 29 August, 20214 yr by john999boy
Highly relevant typo.

So just as an update I’ve now replaced the coils and also done the plugs and I’ve still got the same issues however I’ve now also ordered a new pvc valve with both the pipes and will see if it was just a dodgy pvc valve I had 

Any DTC codes>? 

 

A genuine fine oil separator / PCV from VAG?

 

 

I got a million codes all saying misfire on all cylinders and also saying I have an air leak system it was an eBay pvc but Ive now ordered from main dealer to see if it was a doggy pvc valve to be fair 

I got a million codes all saying misfire on all cylinders and also saying I have an air leak system it was an eBay pvc but Ive now ordered from main dealer to see if it was a doggy pvc valve to be fair 

So just an update replaced the PVC valve for another genuine 1 and the car is now running perfect again ! So guessing it was just that but least the plugs and coils been changed tho I guess 

Maybe not I’ve got a code of po171 !!!

Could it be the maf sensor ?

Don't think so. It is likely vacuum related isn't it?  Check the tabs and pipework to the PCV you've replaced. Some clips tend to break and could leave a vac leak. Otherwise check other vacuum lines.  pattern PCVs on these engines are almost  always worthless  (I don't think I've ever seen a post of someone successfully using one_ and create no end of problems!