pesky check engine light ?

1999 Chevy Malibu 4 cylinder

alternator went bad - light on
new alternator - light out

light on - found deteriorated vacuum hose.
cut end off hose and shortened it - light out.

light on - found fuel pressure regulator leaking fuel.
new regulator - light out.

this morning on way to work light back on.
getting monotonous. almost ready to have a bon-fire. car just passed 100,300 miles. all this light stuff in less than 2 weeks. taking it today to get light read.

I just switched to 5W30 AMSOIL and hopefully this is not related. though i can hear the engine louder now than in the past. before i never actually heard the engine but now it almost sounds like piston slap. dont rightly know what piston slap sounds like though to be honest. never been an issue.

First thing you need to do is pull the codes..
Autozone can do this for you.

went by AA and got them to check the codes whilest i was getting tranny supplies to change that filter and it had some number on it which i didnt get to write down cause he cleared it so fast but i did read where it said the number then "low voltage sensor" but he was nice enough to clear it for me. so far about 60 miles and it hasnt lit back up.
changing the transmission filter was easy. and i reused the factory gasket. the flimsy rubber one in the kit was nothing compared to the stocker that was in great shape no dimples or voids anywhere on it. so i used it. put in a little over 7 Qts and it leaked some then dribbled so i have it at the right level. having family with a grease pit made that a lot easier. and it shifts a lot better now. used Valvoline maxlife fluid.

maybe i'm good for a while. i'm hoping at least till we get this surgery behind us and Wife gets better.