Throtel body isc sensor problem

Is ETHANOL in the fuel? Causing major problems because it attracts water.

You didn't specify year make and model. There may be no problem with IAC valve and have changed it for no reason. There could be something else affecting the idle and causing the computer to store a false code. You may have a vacuum leak resulting in improper IAC operation thus setting a code.

use a scanner to find fault code, if no codes, check fuel system

Sounds like a plug or coil pack issue. Might try cleaning the throtel body first

Error Code: P0130
Fault:
Oxygen Sensor (O2S) 1, Bank 1 - Circuit Malfunction
Possible Cause:
Malfunction Indicator Lamp (MIL) Triggered on first occurrence.
-Wiring harness.
-Oxygen sensor (O2S).
-Engine control module (ECM).

Error Code: P0505
Fault:
Idle Speed Control (ISC) System - Malfunction
Possible Cause:
-Wiring harness.
-Idle speed control (ISC) actuator/Idle air control valve (IAC) valve.
-Throttle motor.
-Throttle valve tight/sticking.
-Engine control module (ECM).

Error Code: P0100
Fault Location:
-Mass Air Flow (MAF) Sensor/Volume Air Flow (VAF) Sensor - Circuit --Malfunction
Possible Cause:
-Wiring harness.
-Mass air flow (MAF) sensor.
-Volume air flow (VAF) sensor.
-Engine control module (ECM).

Error Code: P1491
Fault:
Exhaust Gas Recirculation (EGR) Valve Insufficient Lift
Possible Cause:
-Wiring harness.
-EGR Valve.
-ECM

Error Code:P1607
Fault:
-Engine Control Module (ECM)/Powertrain Control Module (PCM)

Error Code: P0966
Location:
-Pressure Control (PC) Solenoid B - Circuit Low
Possible Cause:
-Wiring short to earth.
-Pressure control (PC) solenoid.
-Engine control module (ECM)/Powertrain control module -(PCM)/Transmission control module (TCM) .

mass air flow sensor measeres the air intake for the engine not sure exactliy where its located on a toyota corolla but it is usualy located between the air filter box and the throtel body or some times its mounted on the throtel body

the three things your vehicle needs is spark fuel and air. so check to see if all your wires are getting good spark. now for the air you have the air filter then right behind it you have your mass airflow sensor then you will follow the air induction up to your throtel body. make sure your throtel body is in good working condition I.E depending on if you have a electronic throtel body or the old cable version you also may clean the throtel body along with the mas airflow sensor. in the rear of the air induction there is yet another sensor called the map sensor check this for serviceabity also. if this does not solve the problem your fuel lift pump in your fuel tank will have a constant hum to it easy way to tell if this is the isue is unhook your fuel supply line and turn the key to the on position this will tell you if your fuel lift pump is working another thing to check is the charcol canister it may be clogged

2 bolts on the sensor on the rear of the throttle body should be 10mil

it is probably the driver fuel pump modual (DFPM) it is located above the spare tire. they usually corrode away and shut dow the fuel pump intermittently. u may also have to replace the connector to due to corrosion