When a "normal" code is output during a dtc check but the problem is still occurring, use the problem symptoms table. The suspected areas (circuits or parts) for each problem symptom are in the table. The suspected areas are listed in order of probability. A description of each of the chart's columns is below.
Hint: in some cases, the problem is not detected by the diagnostic system even though a problem symptom is present. It is possible that the problem is occurring outside the detection range of the diagnostic system, or that the problem is occurring in a completely different system.

Diagnostic trouble code chart
Circuit inspectionReplacement
Replace timing chain cover oil seal
Using a screwdriver and hammer, tap out the oil
seal.
Place the oil seal retainer on wooden blocks.
Apply multi-purpose grease to the lip of a new oil
seal.
Notice:
Keep the lip free of foreign objects.
Using sst and a hammer, tap in a ...
Catalyst system efficiency below threshold (bank 1)
Monitor description
The ecm uses sensors mounted in front of and behind the three-way catalytic
converter (twc) to
monitor its efficiency.
The first sensor, the air-fuel ratio (a/f) sensor, sends pre-catalyst
information to the ecm. The second
sensor, the heated oxygen (ho2) sensor, se ...
System voltage
Description
The battery supplies electricity to the ecm even when the ignition switch is
in the off position. This
power allows the ecm to store data such as dtc history, freeze frame data and
fuel trim values. If the
battery voltage falls below a minimum level, the memory is cleared and ...