das280zx

I have a 2000 crew cab v6 frontier with the vg33e. Well I towed a boat with it this past weekend. Going up a fairly steep grade, I noticed it pinged very badly. I could reduce the pinging by backing off the gas, but it still pinged all the way up the hill. I have noticed the truck pinging before, but only once in a while. Well I discovered from looking at my Haynes manual, that you can run a "self diagnosis" through the check engine light. The ecu flashed the code for "knock sensor fault" and that is the only code it flashed. I am guessing that the sensor is bad, but who knows for sure. The sensor is buried under the intake manifold and looks to be a real PITA to remove! I can do it, but would like some ideas on my problem before I dive in. Thanks for the help!

SPEEDO

how about the gas, bad or low octane gas will ping. at least it does in my hardbody. I would try a higher octane and if it still pings, go after the knock sensor, which will probably get replaced anyway

b67

I agree, when your going to tow try the high octane - especially in hot weather

lewisnc100

What plugs you running, OEM? Plenty of posts on pinging especially under load without the OEM plugs. The knock sensor error code is very common but will not activate the check engine light, I get the same error all the time without pinging. You can also test the knock sensor at the sub-harness connector to verify if it is OK, mine tested out fine.

I would definitely look elsewhere before trying to get at that sensor, mine is in the same location and looks like a real pain to get to.

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1997 Pathfinder XE
Air Lift Air Bags, Warn Hubs

das280zx

Thanks for the replies. Maybe I just need a tune up. I have about 70,000 miles on the rig and have done nothing. It still has the original plugs, wires and distributor cap.
lewisnc100, what sub harness connector are you talking about for testing the knock sensor? I think the knock sensor comes off of the fuel injector harness, so I found a big plug that comes from that harness, that was on the right valve cover. It had a white wire in it, which I guess is supposed to be the knock sensor's wire's color. I tested the resistance of this wire and got around 550 k ohms, which is about what the knock sensor is supposed to be. I am not sure this is the right wire though, as I only have the haynes manual and it is not very specific. Thanks for your help!

das280zx

still wondering what sub-harness connector and wire to test for the knock sensor. I think I got the right one, but am not completely sure. Can anybody help? Thanks

lewisnc100

Just follow the line out from under the intake manifold to the first subharness connector, mine has 2 right together and the one to test is the driver side one. The connector on my Pathfinder had 8 terminals, testing from terminal 5 (bottom left terminal) to engine ground should be 500-620 k ohms at 77 degrees F.

__________________
1997 Pathfinder XE
Air Lift Air Bags, Warn Hubs

das280zx

Thanks, that is kinda what I did, but on my frontier, you cannot follow where the wire comes out. I think it comes out from under the back of the intake manifold and then joins the injector harness and then comes out to the connector on the valve cover. I did check a white wire on that bigger connector that read about 550kohms, so that would probably be it.