i have a 1995 monte carlo ls with the 3100 sfi motor and i had a check engine light go on so i had a mechanic read the codes and came back with a code 44 lean, a code 43 ESC module, and a code 28 tranny pressure switch. the mechanic told us to not worry about the code 44 and 28 and to worry about the ESC and i can't seem to find it at all. he also said try changing the knock sensor and thats easy and only 30 dollars so ill do it anyways and i have a thermostat to change also. so if you could me in finding this ESC it would help a lot.

here are my symptoms anyways:
rough idle maybe between 800 and 1100 rpms radically almost to the point were it cuts off( scary at red lights. maybe carbon build ups i mean its almost 20 yrs old)
one morning first start of the day at about 6 in the morning didn't even make it out the neighborhood and it just died out wouldn't start for a few minutes but when it did it revved super high like 4000 rpm for at least thirty seconds and thats not normal.(possibly sucked some bad gas? idont know.)
hard shifts from first to second and third to fourth sometimes.( i added some lucus stop slip additive to the fluid and it seemed to help a small amount not much)
i was also told my aftermarket radio and amp with my sub could be having an effect i was wondering if i should run a capacitor or maybe upgrade to a better alternator)

if anybody has any information on any of this or this has happened to you i would greatly appreciate your answers. this car is starting to grow on me an i want it to keep running.

 

This Link should be some valued Help!

GM 3.1 and 3.4 V6 Engine Operation | Chevy Buick Pontiac Oldsmobile