help..check engine again

[dindy]

.....got some trouble issues with my 2002 1.0 auto vitz.....once check engine light is on...mech told me it is the afm sensor...changed..after some trips again change engine light with rough idling.....again mech told me it is the idle control valve......changed this expensive part about 250 euros.....now again!!! rough idling and check engine light is on , but the myth is this....when i start the car i got good idle and good start. no trouble...but after a few drive about 30 minutes the check engine light kicks in. but driving is good condition, but when i stop to idle , it is like shaky u hear like hissing noise under the bonnet. then i turn off the engine, start again....no rough idle no cel, but then again after 30 mins of drive it pops on again.....now i notice a new problem...ac wont kick in since i got this f"$%£ problem....need some help pls i already payed alot of bugs on mechanics and other sh!t...

changed....spark plugs, air flow meter, air filter, trassmission oil, engine oil, idle control valve. parts from original toyota dealer.