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1999 Nissan Maxima GLE with P0306 and P0325: Misfire and Knock Sensor Issues Explained

Model: 1999 Nissan Maxima GLE Fault Code: P0306 Posted: 2012-02-28 16:29

Hi all, I recently purchased my 1999 Nissan Maxima GLE in August and have been experiencing recurring issues. I've already replaced the starter and battery due to starting problems—my car would take several attempts to start, which led me to replace the starter. Around that time, the check engine light came on with a knock sensor fault (P0325). After replacing the starter, the issue disappeared temporarily. About a month ago, the check engine light returned. The car ran fine at that point, so I ignored it. Just over a week ago, after filling up with cheaper gas, my vehicle began idling roughly—feeling like it was shaking. We initially suspected water in the fuel due to the cheap gas and used an Auto Zone fuel treatment. The shaking stopped the next day but returned four days later after refueling. On weekend drive, when I pressed the accelerator fully, the car only reached 40 mph—this is the first time this has happened, so I was concerned about transmission issues. I took it to a mechanic yesterday, and during the visit, the car ran perfectly—no shaking or stalling. The check engine light now shows two fault codes: P0306 and P0325. As a first-time car owner on a bank loan, I'm trying to fix this as affordably as possible. Any advice or guidance would be greatly appreciated. Thanks in advance!

Related fault codes

P0306P0325

Comments (6)

Anonymous 2012-02-28 17:07

Hi rplasenc — thanks for sharing your situation. The P0306 and P0325 codes are key here. P0306 indicates a misfire in cylinder 6, which is one of the cylinders in the V6 engine. Since the 1999 Nissan Maxima GLE has a transverse V6 layout, cylinder 6 is located closest to the driver's side and front bumper. To troubleshoot: - Remove the spark plug cover and locate cylinder 6 (on the left side when facing the engine). - Check the spark plug for wear or fouling. Use a spark tester to verify spark from the coil. - Inspect the ignition wire resistance—should be around 500 ohms per foot—and look for visible spark jumps or tracking on the distributor cap. P0325 is typically triggered as a secondary symptom of misfiring in cylinder 6, because the knock sensor detects abnormal vibrations. Fixing the misfire should resolve both codes. Start with these steps and let me know how it goes—this is often a manageable fix for early V6 Nissan engines.

Anonymous 2012-02-28 17:19

P0325 (knock sensor fault) in a 1999 Nissan Maxima GLE is common, but it's not usually the root cause—it's typically triggered by misfires. Many of these vehicles have known ignition coil issues. If spark plugs don't resolve the problem after replacement, a faulty ignition coil should be considered—especially for cylinder 6.

Anonymous 2012-02-28 20:15

It's better to diagnose and fix the actual root cause rather than replacing parts blindly. While part replacements can help, they're not always effective without proper diagnosis.

Anonymous 2012-02-29 06:25

Are you referring to my advice? I appreciate your response.

Anonymous 2012-02-29 09:49

I agree with most of what you said. What stood out was your suggestion that 'if new spark plugs don't fix it, consider a bad coil.' While I understand the practicality, I'd prefer to identify and fix the root cause first—especially since ignition coils are common in Nissan V6 engines. A simple swap between cylinders can help confirm if the issue is with one specific coil before replacing parts wholesale.

Anonymous 2012-02-29 17:31

I agree that diagnosing the actual fault is more effective than swapping parts. However, many car owners don't have the tools or knowledge to properly interpret diagnostic codes or perform in-depth testing. In real-world experience at my shop, many Nissan V6 engines—especially from this era—have recurring ignition coil failures. While not every vehicle needs full coil replacement, it's a known pattern: swapping coils between cylinders (e.g., cylinder 6) can help isolate the faulty unit before buying new parts. Some Nissans have official Technical Service Bulletins (TSBs) confirming this. The key is to diagnose first, but don't overlook that some issues require full coil replacement for resolution.