My car has had rough idle and sometime stall. The problem is; it is a very intermittent issue and whenever I brought it to my mechanic, the problem wouldn’t be present. I had the engine light on so we hooked up the diagnostic tool. There were a whole bunch of codes that showed up and everything pointed to fuel related issues. My mechanic told me that the problem is not very obvious and to make things worse, the intermittent nature of the issue makes diagnosis even more difficult. There are a couple of possibilities and he suggested we start by replacing the least expensive parts and see what happens.
By now we replaced the throttle body (it was my suggestion), the air mass flow sensor, the fuel pressure sensor, the fuel pump module and the fuel filter but I still have the same issue.
My question is; is it reasonable at this point to expect that he all future repairs related to this problem be free of charge? I do see his point and I am not sure what else I would do in his place but on the other hand I am getting frustrated and frankly, I feel like I am paying for nothing.
What would be a reasonable expectation on my part towards the garage?
Thanks in advance.