Recently, my car has started stalling when I take off from a stop right about when I shift into second gear. It also lugs down while I'm driving down the road. Sometimes, it'll start up great, and other times it takes about half an hour to get it to start and run good enough to get down the road. We changed the air filter, oil filter, and spark plugs. The fuel pump is new, and seems to be working fine, and we treated the gas for water. A mechanic told me that he couldn't hook my car up to the machine to check it, but he guessed that it was a mass air flow sensor problem. I bought a used oine, but it seemed to go bad in two days, so I bought a new one. I'm still having problems. I was told that the new part can be bad, to replace it again, or the car may have a bad wire, so I need to replace the wiring harness. What do you all suggest? Thanks for any help you can send my way!