Why would a cold idle speed be 1500rpm when it's hot outside? on 2000 Toyota 4Runner

It's a 90 degrees out every day. The light came on and the code read- rich mixture problem. There isn't any gas smell from the air filter. I bought a new gas cap. May have to get new o2 sensors. The intake housing coupling (the accordion one)cracked and was repaired with black silicone.

Asked by for the 2000 Toyota 4Runner
1 answer 2 comments
what are your eng codes?
air/fuel mix system rich (bank 1)
probable cause:
1.injector or fuel pressure regulator leakage
2.faulty MAF/VAF sensor
3.ECT faulty
4.Faulty H02S/AF sensor
I just had valve cover gaskets and ignition coils installed. Thank You for your help.
reurn and ask if they could have left something unplugged or connected wrong