My manual Se Saloon 2004 5 speed manual had unstable rpm and thereby poor fuel economy.
To rectify the problem I went through the works different mechanics workshops etc, injectors cleaning, injectors changed, fuel filter changed, sprak plugs changed, sensors replaced etc but the problem persisted.
At the end someone told me that Se Saloon throttle develops play over time and bleeds excess air, so throttle body replacement was the only solution.
I replaced the entire intake with a altis intake it's a bolt on fit. I have driven 1000 km since then and the car's rpm is stable and fuel economy seems fine.
I am just suggesting that you may also need to have your throttle thoroughly inspected for wear and tear.
Please have your car thoroughly inspected before replacing anything, you should be sure that your car actually needs the repairs. Local mechanics tend to run us around in circles and waste money on parts etc without actually identifying the real cause of the problem
