Hello, I've been working hard to find a Professional to assist you with your question, but sometimes finding the right Professional can take a little longer than expected.
I wonder whether you're ok with continuing to wait for an answer. If you are, please let me know and I will continue my search. If not, feel free to let me know and I will cancel this question for you.
Hello. My name is Mark and I hope I can help you.
The first thing I need to ask is why were the turbo and injectors replaced. If it was because the problem was the same as you have now then clearly the garage have not done their job properly and should now resolve the problem at no cost to you.
If it were you that asked for the turbo and injectors to be replaced because you had been told they were faulty or you had read somewhere that was the most likely cause then the garage are not liable and entitled to charge for further testing to establish the true cause of the fault and also for any parts that are required and fitting charges.