I have done that already. I have this scanner which I'm using to diagnose my car. The codes use to be, oxygen sensor bank 1, but I've replaced the two catalyst and service the sensors. That problem is gone. But the code remaining and refused to go after replacing the part is:
Idle air control valve. Read my initial post.
The thermostat has been removed and the code is there too but my mechanic said removal of thermostat can not make car to consume fuel

Greetings guys, please I need help.
My Toyota Corolla S 2003 model consumes fuel a lot.
I've replaced both catalyst and plugs yet no solution.

I noticed that the idle air control valve is not working and I've replaced it more than 3 yet this idle air valve refuse to work.

I also noticed that my fuel pump is connected directly to ignition

I also noticed that my thermostat has been removed and the fan is on direct ignition. Please somebody should help me

Please guys I need help, my Corolla is consuming too much fuel. I've done all my possible best but no solution.

*I've replaced both catalyst
*Change plugs
But two things I noticed that are not working are:
* The thermostat have been removed and the fan runs whenever I put on the ignition.
* Idle air control switch not working.
I've changed more than 3 injector heads still the idle air control valve refuse to respond. I'm confused. Please somebody should help