in my car 1.3L 2szfe engine, changed the plugs, throttle cleaned, cleaned both catalytic converter. perfomed the above mentioned job so i can use regular fuel as i am using premium fuel for almost 3 years. my car engine knocks and pick up is slow on regular fuel. even after performing all above remedies problem is still there. i guess i will have to use hi octane throughout as my mechanic says. someone told me to clean fuel injectors or adjust timing but i don't know if that will make any difference.??
