I have been trying to get this code to go away. My VSC Light off blinks and Check Engine Light will also blinks. I finally got this code. I have swapped coil packs from 1 to 2. And I have replaced all 4 plugs with new NFL. There was a bunch of gunk on Cyl 1 plug.
All four were whitish. I have 193k miles. It uses oil quite a bit between oil changes. I also dumped a bottle of Seafoam in the tank at a half tank and let it run for about a hour. Hoping it would help clean out the injectors. I'm dreading buying a new injector
because they run $137. It will hesitate when giving throttle some times. But at idle and light throttle it's smooth. Help.

 

You've tested the usual stuff. Next step is injectors. Maybe try swapping 1 & 2 to see if it moves. Also did you clear the ECU after you swapped the coils to make sure it was reading a new code?

 

yep cleared the code. Well I will swap the injectors this weekend. Thank you

 

I tried several apps on my phone. Toyosys free finally gave me the right code for an O2 sensor. At 193k you could have another one go bad.
Use Top Tier gasoline