What I would do if this happened.
1. Disconnect the battery for 30 MIN(can do wonders sometimes.)
2. Then plug back and start, issue not gone, plug in a OBD Scanner and check for error codes(maybe erase them if possible).
3. Check the obvious sensors like O2(Ive had an issue with a O2 sensor before that triggered the 4LOW light for some reason).
4. Take it to the toyota dealer.
Good luck.
1. Disconnect the battery for 30 MIN(can do wonders sometimes.)
2. Then plug back and start, issue not gone, plug in a OBD Scanner and check for error codes(maybe erase them if possible).
3. Check the obvious sensors like O2(Ive had an issue with a O2 sensor before that triggered the 4LOW light for some reason).
4. Take it to the toyota dealer.
Good luck.