The car is very slow to build up revs in gears 1 and 2. Takes an age to accelerate then pulls and enables a gear change. Fine on the motorway and drives normally. Tried some catalytic cleaner on advice and performance has improved though still a hint of sluggish acceleration. Various advice from wrong oil, to air sensor but it's a real mystery. The cat fault light is now on but each time I take it to garage the mechanic is reluctant to name the problem and say several faults are registering. Also had two weeks recently of perfect motoring after clutch and starter motor replaced, then old problem returns. Has anybody had this problem?