Oxygen Sensor
- Disconnect oxygen sensor connector. Start engine and warm up for 2 minutes at 3000 RPM under no load. Raise engine speed to 4000 RPM and release the throttle suddenly at least 5 times.
- Within 1 minute after engine has been warmed up, measure voltage between connector terminal and body ground as outlined in steps 3) and 4).
NOTE: If it takes more than 1 minute to complete checks, warm up engine as outlined in step 1).
- Raise engine speed to 5000 RPM, then lower to 2000 RPM by operating the accelerator pedal. Immediately turn ignition switch off. Voltage at the terminal should read 0.4 volts.
- Disconnect vacuum hose, between MAP sensor and throttle body, from throttle body. Plug opening in throttle body. Connect a hand vacuum pump to open end of vacuum tube and apply 12 in. Hg vacuum and raise engine speed to 4000 RPM. Voltage reading should be 0.6 volts. Replace sensor if voltages are out of specified ranges.