Test TC-8A - O2S Stays Above Center (Rich) (DTC 52)

WARNING: This page is about a different car, the 1995 Dodge Dakota. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: For circuit and connector terminal identification, see CONNECTOR IDENTIFICATION . For wiring diagrams, see WIRING DIAGRAM section.

Start engine and apply parking brake. Using scan tool, set engine speed to 1500 RPM. Using scan tool, read Oxygen Sensor (O2S) voltage. If O2S voltage is always more than .5 volt, go to step 3). If O2S voltage is not always more than .5 volt, condition required to set DTC is not present at this time. Go to next step.
O2S STAYS ABOVE CENTER (RICH) DTC sets if O2S output voltage stays at more than .5 volt, but less than 1.2 volts, without changing for at least 8 minutes. Possible causes are: high fuel pressure, other engine sensor calibration failures, ignition system failure, O2S failure or mechanical engine failure. Go to TEST NTC-1A.
Check O2S connector for excessive dirt and/or grease build-up. Closely check O2S connector between Dark Green/Orange wire.
If excessive dirt and/or grease build-up is present, clean O2S connector as necessary. Perform TEST VER-2. If excessive dirt and/or grease build-up is not present, a condition causing engine to run rich is indicated. Go to TEST NTC-1A.