Hi, I recently purchased a C5 2008 petrol 2.0 automatic Executive, on returning from the garage this developed a fault. At first the engine cut out when driving at low speed, this was coupled with a stalling/loss of power at cold engine start. I also noticed a throttle delay, especially around 2nd gear. My local dealer diagnosed an issue with the injectors (that cost £110), they wanted another £200 to further identify the fault. The garage I bought it from took it back under their warranty and replaced the fuel pump and the fuel filter. This appears to have solved the engine cutting out but the other 2 issues remain, there is still loss of power/juddering at cold start (last 5-10 seconds) and a throttle delay when driving, up to 2 seconds when i put my foot down. The garage have now replaced one of the fuel injectors that they said looked "different from the other 3", this made no difference, they clearly don't know what the issue is, can anyone help?