Citroen Xsara Picasso fault code 2007

Over last couple of days before breakdown car was sometimes taking a couple attempts to start and sometimes I thought car wasn't picking up speed but on and off. On day of breakdown I slowed the car down to give someone my car park ticket and then car cut out and wouldn't start again. After a few attempts it started but there was no acceleration and car cut out again. Then engine light came on saying engine fault. The more I trued to restart the longer the car stayed on for. Accelleration came back after a while and by the tine green flag arrived car was cutting out after a minute but no engine warning sign any more. Green flag read ciodes p2111 , p0069 , p1351 after disconecting some cables and resetting computer it read fault codes p1471 and p0122 and p2111. When it was towed to garage next day car starred ok and mechanic could drive it and left it running. But after reset fault code p2111 came back on. He has now replaced the accelerator pedal I think , he said part was 92 pound plus vat . Still not fixed fault code. He is trying to get a second hand throttle body to see if it's that. But then he said if not its expensive wiring job. Anyone help please.