ive got high milage vectra elite 1.9 dti150 estate runs great with no problems but i just bought an op-com an came up with egr faulot code po400-5a exhurst gas recieculation flow insufficiant so thought i would clean out egr valve it was blocked solid and not working at all. anyway cleaned it freed it all off and put it all back and now have 2 codes
P0400 - Exhaust Gas Recirculation Flow Insufficient Detected
(5A) - Not present
P0400 - Exhaust Gas Recirculation Circuit Open
(04) - Not present
so question why have i now got second code and 2 am i doing any harm driving car. it runs fine with Know warning lights