Circuit Description

PCM can identify if vehicle fuel system is capable of supplying adequate amounts of fuel during heavy acceleration (power enrichment). When a power enrichment mode of operation is requested during closed loop operation (by heavy acceleration), PCM will provide more fuel to engine. Under these conditions, PCM should detect a rich condition. DTC will set if a rich condition is not detected at this time. A plugged duel filter or restricted fuel line can prevent adequate amounts of fuel from being supplied during power enrichment mode.

DTC will set if O2S1 voltage is less tan 300 mV for 5 seconds during power enrichment mode and following conditions have been met:

• DTCs P0131, P0132, P0133, P0134 and P1133 are not set.
• ECT greater than 68°F (20°C).
• Engine running more than 20 seconds.
• System in closed-loop.