GS300 Oxygen Sensor / MAF
My 1998 GS300 check engine light came on so I had the codes read at the auto parts store. They revealed.
P0100 MAF Malfunction
P0130 HO2S Circuit Malfunction, Bank 1 Sensor 1
P0133 HO2S Circuit Slow Response, Bank 1 Sensor 1
P0171System Too Lean (Fuel Trim)
P0153 HO2S Circuit Slow Response, Bank 2 Sensor 1
A couple of months back I took the car in for service and they replaced an "air flow" sensor. ($45.00 part plus $250.00 labor) I don't have the details for this part. Regardless, the check engine light came on 2 days later. The parts store suggested both oxygen sensors and possibly the MAF.
This car has 115K+ miles and has had very little maintenance, other than oil changes. It is a little sluggish during initial acceleration, but runs ok otherwise. Before I got both sensors and the MAF, I wanted to run it by the experts on the board.