Troubleshooting overheating

i deliver mail and on hot days with the stop and go my check enging will come on, when tis happens the car will not wan’t to move easily, the rpm goes faster than the mph, smells hot. if i keep rpm under 2 car will continue to move and can finish driving for 2 hrs. i let it cool down and light goes out and it works fine. also if running the ac it acts up more often

Sounds like it is going into limp mode.

That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P0123) not just their translation into English and post it back here.