Q: P0133 code change O2 sensor two times still sets the same code after about 200 miles.

Hi there. From the description you have given, for your vehicle’s P0133 code (O2 sensor slow response). It could be an exhaust leak near the O2 sensor causing the O2 slow response code. An exhaust leak could draw air in under light load and keep the O2 sensor from generating voltage over .5 volts.

It could also be low fuel pressure caused by a faulty fuel pump or an intake manifold vacuum leak. In either case, your vehicle’s engine running lean could produce the O2 slow response code.

Finally, it could be an electrical circuit problem, such as an open circuit between the O2 sensor and the ECM (engine control module). The Denso O2 sensors typically are quality sensors. I recommend having the Check Engine code diagnosed more thoroughly by an expert technician. If you’d like to have this done, a certified professional from YourMechanic can come to your car’s location to perform this task.