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brownjeff, ASE Certified Technician
Category: Nissan
Satisfied Customers: 13886
Experience:  17 years experience, ASE certified, dealership certified, Service Manager for 15 years,
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1998 I30: emissions..P0325 Knock Sensor 1 Circuit Malfunction..OBD II

Customer Question

Failed emissions inspection because of "P0325 Knock Sensor 1 Circuit Malfunction (Bank 1 or Single Sensor") message plus a number of OBD II Readiness Monitors that are "Not Ready"

What can be done to fix and pass inspection for my 1998 I30?
Submitted: 7 years ago.
Category: Nissan
Expert:  brownjeff replied 7 years ago.
Normally this is due to a failing knock sensor and the reason it is expensive to replace is the intake manifold needs to be removed to gain access to the sensor.
Customer: replied 7 years ago.
Your answer is what I had in my question. Searching the issue indicated that sometimes resetting the codes can clear it up and the fact that others codes were not ready, told me I needed to drive the car farther.

All you've said is get it fixed. The dealer even said, $500, if that is what the problem really is.
Expert:  brownjeff replied 7 years ago.
Do you have a scan tool?
Customer: replied 7 years ago.
No, I do not own a scan tool. If I did or could borrow one, then what?
Expert:  brownjeff replied 7 years ago.

There is a test you can do to determine if it is bad, but need a scan tool. Also with out a scan tool if you have a meter. Here is some information.





1)Turn ignition switch "ON" and select "DATA MONITOR" mode with CONSULT.
2)Start engine and run it at least 5 seconds at idle speed


With Generic Scan Tool

1)Start engine and run it at least 5 seconds at idle speed.
2)Select "MODE 3" with GST.


Without Scan Tools

1)Start engine and run it at least 5 seconds at idle speed.
2)Turn ignition switch "OFF", wait at least 5 seconds and then turn "ON".
3)Perform "Diagnostic Test Mode II (Self-diagnostic results)" with ECM.










  1. Disconnect knock sensor harness connector.
  2. Check resistance between terminal (2) and ground. Approximately 500 - 620 K Ohms at 25°C (77°F)
    • It is necessary to use an ohmmeter which can measure more than 10 M Ohms.




Customer: replied 7 years ago.

1. What is Consult?
2. With generic scan tool, what is GST and how is scan tool connected.
3. How is step 3) in Without scan tools run and what is ECM?
Expert:  brownjeff replied 7 years ago.

The consult is a brand of scan tool

GST is generic scan tool

The ECM is the engine control module

Customer: replied 7 years ago.

What will clearing or resetting the codes do?

Why are some monitor redings by the inspection station reading "Not Ready" and how does one get them "Ready?" I had the battery disconnected for 6-8 hours while I was replacing a battery terminal cable. Does that have any impact on my issues?
Expert:  brownjeff replied 7 years ago.
Disconnecting the battery has caused the not ready problem and will need to drive the vehicle for a while to get them ready.