2004 Corolla Auto 220k kms
Sometimes I feel there is slight lag/ miss when going up in speed.
one friend of mine, mechanic said I need to use injector cleaner to clean them, and this may go away.
His advice was let the petrol level go down (to let light on) add the cleaner, run the car until petrol almost empty.
then refill the fuel tank
Is this OK to do? injector cleaner bottle says add onto full tank
Could be the injectors need cleaning after 20 years. But it could be other things as well. I'd certainly check those decades-old vacuum hoses and fittings for leaks. Scanning for codes and data might reveal other problems.
Scotty recommends ATS Fuel System Treatment. If not available in your country (guessing it's not the U.S. due to "kms"), his next choice is PEA-based cleaners such as Techron or Gumout. Follow the manufacturer's instructions.
