What is a p1133 code on 2000 Chevy Malibu?

P1133 is an OBD-II trouble code that indicates a problem with the Heated Oxygen Sensor (HO2S) - Slow Response - Bank 1, Sensor 1. This sensor is located in the exhaust system before the catalytic converter and its job is to monitor the amount of oxygen in the exhaust gas. The slow response code means that the sensor is not responding quickly enough to changes in the exhaust gas composition.

Possible causes of this code include:

- Faulty HO2S

- Loose or damaged wiring and connectors, especially at connector C101 near bank 1 sensor 1

- Exhaust leaks

- Vacuum leaks

- Faulty ECM

To diagnose this code, the oxygen sensor readings should be monitored using a scan tool. The scanner can be used to view the live data from the sensor and see if it is responding normally. The wiring and connectors should also be inspected for any damage or corrosion. Any exhaust leaks should be fixed, and vacuum leaks should be sealed. If these simple solutions fail, the HO2S should be replaced and retested.