romanlutsk

Hi everyone,
I'm at my wits' end about troubleshooting my 99 ES300. A few weeks ago it threw these codes:

P1354 VVT System Malfunction (Bank 2)
P1133 Air/Fuel Ratio Sensor Circuit Response Malfunction (Bank 1 Sensor 1)

I replaced the Oil Control Valve and the first error disappeared. Later, I've also replaced the Oxygen sensor (by the firewall), but the P1133 keeps coming back every 20-30 miles after I clear it.

I've checked for vacuum leaks and cleaned/bent contacts in the oxygen sensor receptacle, but the error still comes back.
Anything else I can try?

The engine seems to run ok, although acceleration might be a little slow at times.

Also, I've found that it could be "Fuel Pump, injector or pressure regulator fault" - how do I check for that?

Thanks!