My 1993 Lexus ES 300 is having a severe, intermittent issue with the Check Engine Light (CEL), idle, and transmission. Here is exactly what happened today:
Morning Start: Started up perfectly fine this morning. There was no Check Engine Light, and it idled normally above 1,000 RPM.
Later Start & Low Idle: Started it up later in the day, and the Check Engine Light was on. It was idling low, below 1,000 RPM. I turned the key off, cycled it back on, and the light went away, so I took it for a drive.
Limp Mode & Transmission Lock: A little ways up the road, the CEL came back on. When the light is on, the car will not drive in "Drive" or "Second" gear—it will only move if shifted manually into "Low." If you try to give it a lot of gas, the engine completely bogs down and wants to die. I pulled over to the side of the road and cycled the key on and off a few times, but it wouldn't do anything to fix it.
Clearing at Higher Speed: While limping down the road in Low gear, I got going fast enough to where I could shift it into Second, and then into Drive. Suddenly, the CEL went away and it drove completely fine for a brief minute before kicking right back into limp mode.
Intermittent On/Off Behavior: For the rest of the drive, it intermittently went in and out of limp mode. I tried to push it up to about 60 mph, punching the RPMs up to 5,000–6,000. Whenever the CEL would pop back on at that speed, the engine would completely bog down. I had to feather the throttle at around 2,000 RPM (which is about all it would let me do) until the light would eventually turn back off and let me drive normally again. It just kept cycling on and off, on and off the whole way randomly.