Keep getting 2 fault codes 17524 (which I can't find in book) and 16706 (P0322) Ignition/Distributor Engine Speed Input Circuit - No Signal. The latter code seems to be causing following problems:-

Car starts fine from cold. However, car difficult to re-start when warm after filling with fuel. Also occasionally stalling at traffic lights. Usually re-starts, but I get EPC light and car then runs lumpy.

Once cold again and/or reset codes, car starts and runs fine. Recently, car stalled and wouldn't re-start and towed to garage who replaced starter motor, but codes still appearing and car still running lumpy after 'warm' restart as above. Have been told it could be Impulse Sensor or Engine Speed Sensor oiling up. 6 months ago car had reconditioned engine as previous one losing/burning oil, so sensor may indeed be oily.

Where on Skoda Octavia (2001) are these sensors located? Indeed are they one and the same thing by a different name? Are they expensive to replace? What is/are part number(s) for these Sensors? Thanks