Hi guys, my first thread and my sincere apologies for the semi spammy post count approach I did my best to keep things relevant but this is kinda important I don't want to leave a kid stranded. Very happy to be here and thankful for this place!



I picked up a 2000 4runner for my little cousin who just turned 16. High miles but in really solid shape, previous owner genuinely took care of it he appreciated the truck and it showed. Of course 25 year old daily work horse so it has it's issues and gremlins but drives straight and strong.



Well he had a P0330 knock sensor code which apparently is common and a PITA to pin down properly so we did what anyone who bought a 25 year old 2500 dollar truck for a 16 year old would do and bypassed it. We used this video:



https://www.youtube.com/watch?v=r0FbbNsYeGE





It worked and oddly enough also fixed the O2 sensor code but in the process picked up code P0330 coolant temp sensor which looks like an even bigger PITA as it requires a lot more work above my pay grade to correct and is probably a larger overall issue.



Just taking a stab here hoping maybe there was something obvious that we messed with or unhooked or whatever while jumping those two wires for the knock sensor, anyone have any guidance on what it might be? Would be one hell of a coincidence if it wasn't something we did in there....it returns immediately when we reset it. The other original codes never returned after about 20 miles of driving.



Thanks fellas any help is sincerely appreciated!

Dumb thoughts on my part - Why not check wiring on knock sensor and or replace.

I'd say most likely the eng temp sensor's wiring was disrupted doing the other hack - I'd say put it all back how it was and start again doing it the right way and it may turn out better keeping it working as intended by toyota not hackers - Luck.

Not dumb and you're right but im a half banana mechanic and after researching the cost and involvement of that job and how difficult it is to actually correct the issue I felt it was a bit redundant to invest that much into the truck, mind you a truck a 16 year old is most likely going to destroy.

I'm going to splice it all back up correctly and see what happens but it is still an odd coincidence, really thinking we messed with something else in there by accident because otherwise the hack worked.

I've done knock sensors 4 or 5 times (long story) and it's not a particularly hard job to do, just a pain in the ass. All you gotta do is take off the intake, fuel rails and take out one bolt from the timing belt cover if I remember correctly. It was the first "big" job I had to do and back then it would take me all afternoon, but these days I could probably do it in a couple hours now that I've taken the intake/fuel rails off a dozen or two times. It is a little pricey though, forgot what Denso wants for the knock sensors but I remember they were between $100-200. Regardless you could do it in a day no problem

I agree with Devbot. I have replaced twice ( different cars). Each time the wire harness just crumbled, they get so brittle. I wonder if the knock sensors can go bad or if it is just the harness. Regardless each time I did with new parts OEM, not cheap, but I did not want to tear it all apart for faulty aftermarket.

someplace on youutube, is a guy who took a metal bar and drilled and mounted 2 knock sensors to it, then bolted in the engine compartment, then plugged into harness wiht the new harness and "fixed" his problem without tearing things down

Haha that's interesting, that's a pretty skillful hack job! I'm going to try to find that video, if nothing but I would love to see that!

I appreciate the replies fellas, new wrinkle here. The truck wouldn't turn over this morning and I took apart the hack job and reconnected them as original and only then did it start. Tested it beforehand connected and disconnected, it would only start when connected.

Never saw this mentioned before in all the threads I read that disconnecting the sensor entirely would stop the engine from turning over. Strange because it ran as normal for 20 miles and multiple trips with the hack job done, don't see how sitting overnight would have undone the jack job somehow and it seemed solid when I checked it out today to see if it was the culprit. A little befuddled here but we're back to stock configuration and the engine intermittently going into limp mode because of the knock sensor. Also as of now there are no codes but the P0115, P0330 didn't return but that may change after driving it some more.