So a month or two ago i bought a 1996 jaguar xj6 and was having an issue when i deccelerate. It seems that when i let go of the gas the rpms would drop to 500 or below and eventually the car would shut off. The volts would drop at the same time. So i changed the alternator at first to no avail. After some research i changed the EGR valve and still nothing. I swapped out the TB and put a fresh and clean one in with a new OEM Lucas IAC valve and still the problem persists. I did a hard reset(Disconnected negative terminal for five minutes) and everything worked perfectly after that, i thought the problem was finally fixed however the car shut off again last night. Any ideas? Help please, i love the car but cant take having to watch the rpms all the time! IF i let it shut off it usually goes into limp mode and then the check engine light comes on and gives code P1775.