I have noticed an issue with my 96 Camaro RS. It has a 3.8L V6 with a manual transmission. This problem does not happen every time that i drive it just a few times every now and then. When I am driving down the road and kick it into neutral to coast to my road sometimes the amps drop really low and the car will stall. This only happens when I am coming down from like 50+ MPH. Everytime i let off the gas my RPMs dip really low, my blower and lights dim down then if I touch the gas a little they will come back up to normal. I also noticed that it only does this when my temp is a little high. I have replaced my thermostat and have correct amount of coolant in, but occasionally it will randomly raise in temp and then go down quickly. Well this past time it rose and i went to coast into my road and it stalled out. I went down my road just a little ways to my house (under a quarter mile) coasted into my driveway (temp still high) and it stalled again. For the record i have a mass air flow sensor code on my check engine light, not sure if it is related at all? I also checked my water pump, thought this was the problem and the bearing and everything seem to be working properly. It doesn't overheat it will just randomly raise in temp (under any driving condition) then go back down. Any ideas?

 

My guess would be that power drop/lights dimming is a result of the low RPMs not the cause of it. It could be the MAF. If your car came in with just the Low RPM/ Stall after running at cruise speed and no other codes I would suspect the IAC motor of being dirty or "lazy" or the same thing for the EGR valve.

You should get the MAF issue sorted out, it is one of the most important sensors in your fuel management system. Other then that, the first thing I would do is remove and clean the IAC motor and the IAC port area. I would remove, clean and test the EGR valve for sealing. Search youtube for "Cleaning IAC" and "Clean and test EGR" The only thing you should have to buy is the EGR gasket. Also search "how to set GM IAC" The IAC will reset it self over time but if you do the process it will start easier right off after the cleaning.