I drove through a large puddle a while ago and the van went into limp mode when restsrted. Code 17964 negative deveation in pressure. So i,v changed all vacume pipesand no better so just put new n75 valve on cleared the code. Was ok until got it into 5th on motorway and back into limp mode and code is back. Any one got an idea what could be up with it. O its a 2.5 102 T4. cheers.