just out of curiosity would a k@N air filter cause my subaru to misfire?

 

No. There must be an underlying issue.
You don't say if it's a panel filter or cone as part of an induction kit.

JohnD

 

its the whole thing mate,comes off the inlet manifold and round then got a cone on the end

 

No it won't got one on my car

 

just cant find why my car is hesitant when i accelerate,changed everything including engine,had fuel pump checked thats all ok,had emissions test,lambda and everything else all good.
really fed up now

 

i thought that the induction kits like K&N's that are paper and oil covered draw particles of oil onto the maf which causes maf failure. i had had hesitation problems and it turned out to be the maf causing the problem so changed that but also changed lambda sensor 1st due to a mobile mechanic telling me it was that and wasnt, ive got a blitz metal mesh which is dry no oil and works perfect.

 

Take the MAF off and clean it (carefully). You can buy some proper cleaner for it from Halfords I believe.
When using a cone filter the oil they use on them over time gets onto the sensor in the MAF, this leads to holding back issues.
Actually fixed one like this last week.

 

As supplied, K&N filters are not normally a problem. If it's been cleaned and re-oiled generously then it could contaminate the MAF

JohnD

 

K&N are not paper - they're woven material, lightly oiled to catch the smallest particles.
When cleaning and re-oiling spray the outside only!
As I said, as supplied they're not normally a problem although it's not a bad idea to clean the MAF occasionally.

JohnD

 

after the car visited several garages,tuning specialists and changing engine,coil packs,02 sensor,plugs and leads,fuel pump etc etc went into another specialist yesterday and all along it was the cone air filter causing all the issues,took it off put original filter back on and its running as it should so i have now happily put a hammer through the k an n filter and its now in the bin and wont be putting another 1 on any of my cars.