I [recently replaced](http://mechanics.stackexchange.com/q/2878/1536) the downstream O2 sensor in my Toyota Camry. Shortly thereafter, the check engine like came on again providing the following codes:

- **P1135** which I understand to be the upstream sensor.
- **P1155** is a little bit tougher for me to find any information on, but it appears to be the ["Coolant Temperature Sensor Circuit for Coolant Heat Storage System"](http://www.dtcdecode.com/P1115/Toyota).

When it comes to making these types of repairs, I'm a novice but am interested in resolving these issues on my own if possible.

My two questions are:

- Does anyone know if **P1135** and **P1155** are related?
- If so, will replacing the O2 sensor resolve both codes?