Hi guys I have a previous post about this problem but as iv checked error codes and 2 came up then it's slow progress, I have a modified octavia vrs which has an intermittent misfire it will only happen once every 300-500 miles then will carry on unless the codes are cleared. My crank breather hose was flat so changed that but made no difference and changed vacuum hoses. The car will sometimes do it on around 0.5-1bar of boost or can be up to full boost of 1.8bar so it's not just on full load,

Iv read a past email from a previous owner to "awesome performace" saying about a misfire which was cause by the n75 valve which had been replaced twice but surely that would have a different error code wouldn't it? Thanks

Sorry I missed out the 2 error codes are missfire on cylinder 3 + 4.

Lots of possible causes for misfires.

Plugs,gap,coils,wiring,compression,vac leak,boost leak

If it is mostly at high boost then plug gap or weak coilpack

If it is intermittent might be coil pack wiring or weak coil.

Have you checked the plugs.

Have you tried swapping 3 and 4 to 1 and 2. Reset the codes and then run again and check if the codes move

No I havnt tried that yet bud I was just gonna buy 2 new coil packs and new set of plugs but your idea works out much cheaper, I hope it is plugs or packs, thanks for your reply I will give that a go

Is your car subject to the coilpack recall?? Could possibly get 4 coilpacks for nowt.

Not sure mate how would I know? It's a 51plate and highly modified so that may be their excuse not to touch it

Take it to local Skoda dealer, they can only say no at worst.

Mine is modified to the point where they tried to do the checks after changing coil packs and all it said was "too low to access ramps or anything"

So I'm sure you'll be fine.

Maybe your missfire problem can be the Ignition Module 4D0 905 351  There are many topics about this on several VW Forums

 

http://uk-mkivs.net/forums/p/394834/3621404.aspx#3621404

 

Good luck,

 

Isaac

Edited 27 July, 201312 yr by Turbo_Boss

That module isn't on the auq engine. So it won't be that.