I've had a 2001 V6 Camry(2nd Hand), now 10 years old and have done all the servicing on it myself. All I do is change the oil and filter every 6 months, regardless of distance traveled. Air filter, usually located inside the big black box on the right hand side(looking from the front)changed every 2 years, simple job. All the rest are just check this, check that and look for anything out of the ordinary. try to change the brake fluid and radiator coolant at 4 year intervals. Also have a 2005 Corolla hatch and it gets the same treatment, except radiator and transmission fluids generally don't need replacement on these. Only ever used standard ULP in both, and Castrol GTX3 for oil. In all that time the only major problem was an oil pump failure in the auto transmission(Camry). A couple of rubber boots on ball joints and steering rack..Injectors have never been cleaned.