Can a vacuum leak cause a P0301 Cylinder 1 Misfire code?

Question

I have changed my spark plugs and have switched coils between cylinder 1 and 3 on my 2004 Subaru Forester XT, but the problem is staying in cylinder 1.

The car has trouble starting, very rough idle, hard brakes, and very minimal power. The shift between gears (automatic) seems to have a mild clunk.

I'm trying to figure out if I should start messing with the fuel system or try to find a vacuum leak.

Answer 1

HI there

A vacuum leak can cause a misfire, typically the leak would have to be along the intake manifold for it to cause a misfire however.