bobbyg08

I have had my 08 es350 into the lexus dealer and to a local shop for the last six months to try and find out why I keep getting the codes po172 and po 175. Neither place could figure it out. Both codes indicate (Rich condition on bank !) and (Rich condition bank 2) respectively. When the codes set, I get VSC, Check eng. and Traction Conlrol lights come on. To date, I have spent $1000 dollers on the following: 1. Installed a new Mass air flow sensor, 2. Installed both O2 sensors 3. Replace a supposed bad coil pack 4. Installed a supposed leaking gasket on the intake manifold 5. Replaced the air filter 6. Replaced spark plugs 7. repaired a supposed loose connection on another coil pack 8. Cleaned the new Mass Air flow sensor, 9. Checked all fluids A OK 10. Supposedly Checked the fuel Pressure Regulator for proper pressure. A Ok 11. Tighted a loose hose on the intake. 12. Replaced the PCV valve. All of the above has been done by either the dealer or the shop to no avail. I am at my wits end with taking the car to both the lexus dealer and to a certified shop. Does anyone out there in forum land have an Idea on how I can correct the problem without removing and replacing every systerm in the car? Help!