I have a 2016 camry le lately since I drive uber I have been replacing parts that have worn or have started to fail. I need to know if I should take the car to get a full idle reset or if it's an ecu or injector issue. I may need to replace my spark plugs again since I drive so much so that is also on the list. In park my car idles fine. After driving for a while when I stop my rpms drop and I can feel the car shudder a but. Also when I'm stopped and parked I can feel the car sputtering. Should I replace or clean my injectors. I do use engine cleaner in my gas regularly. I am throwing no codes what-so-ever my cars check engine light has never gone on so I don't even know where to look or begin. I did recently replace the throttle body and the water pump. The pump cuz I was leaking coolant like no other and my throttle was too toasty to get it actually clean enough to put back in. I'm running a 220 amp alternator because I also have a pretty large aftermarket sound system. The car hasn't threatened to turn off yet but the rpms drop so low sometimes I feel like it's getting to that point I know this is alot but I really need some help.

 

The issue may the amp load. The standard alternator is 100A.

The larger alternator takes more HP to operate. There types of bass speakers can draw a LOT of current on a surge basis. Surge as in not constant like an electrical light. High and surging amp loads can cause the engine RPM to be lower or vary.

Do some research on installing a large capacitor into the stereo's power supply to try to smooth out the amp draw plus installing a larger battery.

 

Did the idle issue start after the throttle body? I know there is usually a relearn procedure with that but its usually disconnect the battery for install, install new one, reconnect battery, start car and let it idle for a few minutes.
Just an idea...