1998 Grand Marquis codes PO171 & PO174
Hi, I have a 1998 Grand Marquis and have been having some idling and acceleration problems. Recently I had a starter problem and had the car towed to a shop and had the starter replaced. Immediately after picking the car, the car had hesitation on acceleration and codes PO171 & PO174. (lean fuel mixture bank 1 and 2). Also now when sitting at a stop light idling, the engine surges then almost dies then goes back to normal idle. It does this about every 5 seconds. It only does this while in drive, not while in park or neutral.
When I called the mechanic and told him about the problem he told me since the battery was disconnected the computer had to recalibrate and the problem should go away, and if it doesnt get some carb cleaner and clean the throttle body. That was about 2 months and the problem hasnt gone away.
Ive been trying to look for a vacuum leak but havent found anything yet. Is there any vacuum hoses or sensors down by the starter that could have been damaged while they shop replaced my starter? Or does anybody have any other suggestions what I could check to fix the problem my car has been experiencing? Thanks.