Very rough Idle at stop

Try pulling the plug on TCC solenoid. That should solve your highway to stop problem.

Thanks.

Found the problem. The infamous vacuum leak. Plugged it and the car is purring like a kitten.

My Lumina Euro idles a little rough sometimes, but I am not too worried about that, the main problem is that when it gets hot ( running temperature) it sometimes sputters then stalls. If I give it gas it will restart and I have to keep giving it gas or it stalls if I try driving after the initial stall it barely wants to get out of its own way. I have seen a lot of talk about clogged catalytic converters and also the torque converter lockup solenoid, but I have no idea what to do. The computer comes up with five codes (1)-23 manifold air temp to low, (2)-21 throttle position sensor/ckt high, (3)-15 coolant temperature signal high or open (4)-53 system voltage to high (5)-43 ESC module or sensor circuit problems. Also, the scanner says that my systems voltage is 25.5 volts and the fuel pump is getting 25.5 volts when it is acting up. Please help!

Vehicle has a rough cold idle, usually in colder weather which can last from 15-45 seconds and then abrurtly smooths out.
Previous advice was to replace idle air control valve which was done but this has not corrected the situation.

1987 chevy 454 idles rough but clears out at 35 mph
done a compression check is uneven both banks and have retimed distributor to top dead center, plugwires are new and plug also cap and roto I might have others questions as we go on the 45r