This is probably a common fault but I can't figure it out. I serviced the car last Monday (fuel, air and oil filters). When I started the car it gave an engine system fault and was low on power. I plugged out the electrical connection on the filter and plugged it back in again and the fault was gone but it came back on the Wednesday morning when I started the car to go to work. So Wednesday evening I had another look at the filter and it was a little bit different than the original. So I put the original back in until I got a new one but the fault was still there. So Thursday evening I put a proper Bosch filter in and tried to start it but still got the fault. A mechanic friend told me it's drawing in air from somewhere and the check the hose that comes off it for the seal. That looked ok but I put an O ring over the collar on top of the filter anyway just to get a bit more of a seal. I started the car and the fault was gone. brought it for a test drive and still ok but when I tried to start the car an hour later it stuttered and the fault came back. I left it overnight and when I tried it Friday morning it was fine. I even went on a 4 hour round trip on Saturday and still no problem... until Sunday evening when it stuttered again when I tried to start it and the fault came back. In fact, it also displayed a "power steering failure" error briefly but that went again. The problem persists this morning.
Has anyone else encountered the same symptoms and if so how did you resolve it?