ok i have a question about this problem. i just had a engine swap done to my 98 ex cuz of a cam shaft problem. anyways i got a d16 y7 and had that put in and i had it done on the 9th of september and the other day the 27th i was drivin home and i pressed the clutch in to down shift to 4th gear and the rpms dropped down to 500 and then the car shut off.i turned it back on and it started right back up. got to a stop light and noticed that the car was ideling very low around 500 rpm,and felt like it was gonna stall again.when i got home it was idleing fine.what could be the problem if anybody could help me id really appreciate it.