I just connected my OBD II reader on my 2000 Maxima SE and it gave me these results. Distributor Signal Interrupt , Catalyst System Efficiency below threshold. Being a novice DOY, I absolutely do not know what this means. Short of bringing it to the shop, can anyone explain to me what this means?

 

I cant comment on the DSI, as I cant find a reference of that in the ESM. Per chance is there a numerical code it gave? Might make it easier for me to look up.

But the Catalyst System one might mean you need the TSB that "reprograms" the threshold of the emissions triggering the CEL. Did you have a CEL pop up?

 

colonel,
Thanks for the reply. The code for the catalyst problem is P0420 and the code for the DSI is P1320.

 

DTC P0420 (RIGHT BANK, -B1), P0430 (LEFT BANK, -B2) THREE WAY CATALYST FUNCTION EXCEPT FOR CALIFORNIA

On Board Diagnosis Logic

The ECM monitors the switching frequency ratio of front and rear heated oxygen sensors. A warm-up three way catalyst with high oxygen storage capacity will indicate a low switching frequency of rear heated oxygen sensor. As oxygen storage capacity decreases, the rear heated oxygen sensor switching frequency will increase. When the frequency ratio of front and rear heated oxygen sensors approaches a specified limit value, the warm-up three way catalyst malfunction is diagnosed. Malfunction is detected when warm-up three way catalyst does not operate properly, warm-up three way catalyst does not have enough oxygen storage capacity.

Possible Cause

1 Warm-up three way catalyst
2 Exhaust tube
3 Intake air leaks
4 Injectors
5 Injector leaks
6 Spark plug
7 Improper ignition timing

DTC P1320 IGNITION SIGNAL

Component Description

IGNITION COIL & POWER TRANSISTOR

The ignition signal from the ECM is sent to and amplified by the power transistor. The power transistor turns on and off the ignition coil primary circuit. This on-off operation induces the proper high voltage in the coil secondary circuit.

On Board Diagnosis Logic

Malfunction is detected when the ignition signal in the primary circuit is not sent to ECM during engine cranking or running.

Possible Cause

1 Harness or connectors (The ignition primary circuit is open or shorted.)
2 Power transistor unit built into ignition coil
3 Condenser
4 Crankshaft position sensor (REF)
5 Crankshaft position sensor (REF) circuit

DTC Confirmation Procedure

NOTE:

1 If “DTC Confirmation Procedure” has been previously conducted, always turn ignition switch “OFF” and wait at least 10 seconds before conducting the next test.
2 If DTC P1320 is displayed with DTC P0335, P0340, P1335 or P1336, perform trouble diagnosis for DTC P0335, P0340, P1335 or P1336 first. Refer to EC-391, EC-399, EC-589 or EC-595.

 

Thanks for the information. Its quite alot to absorb and process but with some time and your advice I'll be on the road to fixing my Maxima problems. Thanks to all.