Engine Mechanical problem
2001 Subaru Liberty 4 cyl All Wheel Drive Manual 82500 miles

Hi,
I have a Subaru B4 that was intermittently stalling but would restart. It was sometimes hard to start in the mornings. It has recently stalled and been difficult to restart and now won't go at all.
We had had scan tool on it which diplayed crank angle sensor. This was replaced along with fuel pump but problem just got worse. Scan tool is now showing CA sensor again, along with air flow sensor circuit fault. It has an after market immobilser on it - would this cause any problems?
Engine light now comes on too which it previously didn't.

Thanks for any light you can shed!

Albert