Hi, I have an Audi a4 02, 3.0 auto quattro, the dash light EPC came on and the engine was suddenly rough on tick over, when hot would not start but when cold starts perfect and suddenly the fault would reappear cleared the fault "engine speed sensor(G28) no signal P0322 sporadic 004-no signal/communication," with vagcom, had a new speed sensor fitted and the fault reappeared and the car now still runs rough and will not start when hot. the mechanic is baffled as to the fault. Any idea`s.