I too have this low rpm hesitation problem. I also have a tapping noise when accelerating between stop and 40mph. In 2 years, I've replaced a starter and dealt with a "Bank Lo Lean" check engine code (that suddenly stopped) and now the hesitation at low speeds and the "tapping" noise. The tapping source sounds like passenger side, low on the engine. I've had great luck w/ Toyotas, but my patience is wearing thin with this thing. I've heard suggestions to:
- change fuel filter
- Add Chevron Techron FI cleaner
- Clean MAS sensor
Any ideas on what I should try (above or others)?