Lexus Troubleshooting Questions? Ask a Lexus Expert
Do you have the ability to monitor engine control module data with a scan tool ? Maf readings , O2 , Fuel trim values?
A good visual inspection for any air intake or vacuum hoses disconnected in the engine compartment can contribute to the fuel system lean codes. Most common issue is a dirty or defective mass air flow sensor.
Those lists provided by some parts stores can be miss leading. Those are possibilities that can cause those codes. They are not very common, I have had very good success in cleaning the MAF sensor. Make sure you use specific maf cleaner as you can damage the sensor if there are excessive lubricants or solvents in the cleaner
You may need to see if the parts store will clear the control module memory with a scan tool as sometimes the battery disconnect does not work. Also to answer your first question regarding monitoring the data parameters, most of the generic code readers just display failure code information. You would need to invest a little more to have the ability monitor the data.
I would leave it disconnected for at least 30 minutes, also when disconnected touch the cable ends together. If that does not work a scan tool will need to be used to reset ECM. With both banks setting lean codes it is most likely the MAF is contributing to the problem.
Your welcome, let me know if you need any further assistance.
did you clean the maf sensor and how is the vehicle doing?