I have a 1997 Nissan Maxima SE Auto transmission. When I change gears from PARK to REVERSE my engine dies (RPM GETS REALY LOW). But when I change gears from PARK to Drive everything is fine, engine dies sometimes though. Plus when my car changes gears there seeems to be a pause between gear changes. Also when I brake quickly my car also stalls. When car warms up, it no longer dies when I switch from Park to reverse but transmission shifts rough. My engine codes where Mass air flow sensor, which I just replaced, but my car is still stalls. Now, I have a new code AUTOMATIC TRANSMISSION CONTROL UNIT SIGNAL TO ECU. I have no idea what that means so it would be nice if somebody explained it to me. I was also told to clean my
"IAC Valve" any ideas where it is, is it same as PVC valve. I already cleaned my throtle body.


So guys, any ideas.