WRX is spuddering after a fuel fill up
 

Hi I-Club

I gassed up my 07' WRX after work today at 76 station with 91 octane and noticed as soon as i entered the freeway the lack of power and sputtering around 2,500-3,000RPM. Has anyone else had this problem with bad gas?

I'm trying to figure out if its bad gas or a coincidence.

When i park the car and rev in neutral it doesn't sputter at all it's only when i'm in gear that it occurs.

Any suggestions?

My car is 100% stock. no mods at all

Just an FYI.

LIC Motorsports found the problem to be a knock sensor. It was malfunctioning without throwing CEL.