Update:
Changed left and right pre cat O2 sensors with bosch ones
Car seemed more powerful and exhaust emissions seem a lot less smelly
Later in the day the engine light came on and stayed on (after O2 sensor change)
Previously when this happened the power to the engine was reduced
This time the power to the engine is the same as before the engine light came on
The only other code coming up was for the electronic thermostat
As I was dealing with the O2 sensors I haven't investigated thermostat yet
Will faulty electronic thermostat bring up check engine light or will it just store a code
The water temperature on the dash is in the middle of the gauge
Is the dash sensor the same as the electronic thermostat sensor or is it a different sensor?
Will a faulty electronic thermostat affect the performance of the car? (even though dash water temperature is always normal)
(Will get car codes checked again when I have a chance, but just thought I'd ask for now)
Thanks