Hello and Welcome to Justanswer.com! I need you to answer a few questions for me so I have a better understanding of the situation.
Did the problem occur before or after you replaced the plugs?
Is the check engine light illuminated?
How long has the problem been occuring?
What happens when you accellerate?
Please specify and I will be glad to assist you. Thanks!
Did the problem occur before or after you replaced the plugs? It was internittent before.
Is the check engine light illuminated? It was on (don't know the code) It is not on now.
How long has the problem been occuring? short time
What happens when you accellerate? The engine falls on its face. It has no pickup and is slugish on take off.
I have just submitted a report to have your question moved and addressed in the appropriate Lexus category.
The codes you have pulled from the car are for the intake and air flow meter malfunctions, a couple things to check here. Open the hood and look on the passenger side where the air filter is located, just behind the air filter there is a sensor with 5 wires going to it that is referred to as the mass air flow meter. Check to be sure that this sensor is securely connected. If the sensor is securely conneted then remove the 2 phillips head screws that hold it in and inspect the sensor for contamination or dirt. You most likely have a loose electrical connection here or a defective sensor.