Code 22
- Turn ignition off. Connect a voltmeter to the Green oxygen solenoid wire at the carburetor 6-pin connector and ground. Disconnect and plug vacuum hose at the computer. Connect an auxiliary vacuum supply to the computer and apply 14 in. Hg vacuum.
- Connect a tachometer to the engine. Disconnect the oxygen system test connector and then reconnect Green/White wire only. If equipped with a manual transmission, disconnect the speed sensor connector. Stick a straight pin into wire of the computer 10-pin connector cavity No. 5.
- Connect a jumper wire between straight pin and White/Orange wire of the speed sensor harness connector. Start engine and wait one minute. Raise engine speed to 2000 RPM. Hold oxygen system test connector (open terminal) with one hand and touch the battery positive terminal with the other hand. If voltage reading decreases towards zero volts, proceed to step 4). If voltage does not decrease, proceed to step 8).
- With voltmeter connected to oxygen solenoid Green wire, disconnect hose at computer and plug. Apply 14 in. Hg of vacuum to computer. Connect tachometer to engine and run engine to 2000 RPM.
- Reconnect oxygen test connector. Wait a few seconds for oxygen system to start working. If voltmeter reading pulsates between 7 and 14 volts, proceed to step 6). If voltage is below 7 volts, proceed to step 7).
- Connect voltmeter to oxygen solenoid Green wire. Disconnect hose at computer and plug. Apply 14 in. Hg of vacuum to computer. Connect tachometer to engine and run engine to 2000 RPM. Connect oxygen test connector. Remove air cleaner cover and close choke. If voltmeter reading decreases towards zero volts, oxygen feedback system is okay. Proceed to TEST 13 . If voltage does not decrease, check oxygen sensor wire for an open circuit to test connector. Repair system as necessary. If there is no open circuit, replace oxygen sensor.
- Connect voltmeter to oxygen solenoid Green wire. Disconnect hose at computer and plug. Connect oxygen test connector. Run engine at 2000 RPM with 14 in. Hg of vacuum applied to computer. Disconnect hose from PCV valve and cover orifice. Allow air to slowly enter orifice. If voltmeter reading increases towards 14 volts, oxygen system is okay. Proceed to test 13. If voltage does not increase, check the oxygen sensor wire for a short or open circuit to the test connector. If there is no short circuit, replace oxygen sensor. If there is an open circuit, repair system.
- Connect Green/White wire and disconnect oxygen system test connector. Let engine return to idle speed and then turn off engine. Disconnect computer 14-pin connector. Connect an ohmmeter between test connector (Black wire) on computer side and cavity No. 10 of the 14-pin connector. If ohmmeter shows continuity, ensure terminals in cavity are not spread so they cannot touch the computer pin. If connections are okay replace computer. If there is no continuity, repair open wire to test connector.