Freelander 1 Comercial brain teaser

My Freelander 1 with full LR service history goes into limp mode ( don't know proper term ) every now and again . when connected to diagnostic computer reads " Fuel Rail anomaly " this is without switching off engine, Have replaced all injectors, high pressure pump , hp fuel censor , part of wiring loom even driven car with computer connected went into limp mode, pressed Clear faults on computer vehicle ran fine The Garage I use is a LR specialist so assume they have proper equipment and knowledge