I know this is an old topic but I've got an issue that won't go away. So I had a head gasket failure new to Toyotas!! Replaced had no codes reassembled got ks code this is a 90runner 3.0. Pulled it back apart replaced pig tail and ks with aftermarket. But still getting same issue also replaced the ecm and still at 1800 rpm cel comes on. I'm stumped read lots of post and things but nothing that can really explain why it won't go away. Would old fuel stuck injector cause this?? I'm going bald from this thing!! Should I just drive it for awhile with new fuel??

im dealing with the same thing, replaced KS, ECM, new harness to ECM from KS, basically everything was replaced that is in connection with the KS. Still have code 53 coming on when under load at 1500 or so RPM.

completely frustrated as it was not an easy task replacing now 2 KS thinking the first one was faulty

I too had to replace the KS after a engine rebuild- in case only a OEM KS will fix the issue.89615-20010

Used oem parts, wire had no resistance to ground, I'm stumped

I recently had to to a valve job on my truck as it now has 268,000 on the clock and was having a slight miss. Sure enough on the right head, it had two burnt valves. I used my local rebuilder on heads. I purchased all new gaskets and pig tail for knock sensor and replaces all hoses and related since the motor was torn down and also did timing belt service even though I had just done 4,000 miles prior to this valve issue. Toyota wanted 278.00 list for knock sensor and it was on back order. I ordered one through my local parts house and installed along with new wire pig tail for sensor since my original was hard as a rock.
After everthing was done, I fired truck up and went to adjust timing but it was off. That was an easy fix as I forgot to plug in the throttle position sensor plug. Once that was done, I adjusted the timing 10 degrees as specified in FSM. I drove truck and as soon as I went around the corner, the check engine light came on and truck had loss of power. I checked codes and it was 52 knock sensor. I had my doubts with the non toyota sensor when I installed so now I have taken manifolds back off among all other related parts and have ordered toyota knock sensor and another pig tail. I will reassemble on Thursday. Has anyone else had this same issue with a non toyota knock sensor?? Also, my trucks are bone stock with no modifications other then chroming the factory alloy rims and modern stereo upgrades.

thanks
James

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I used all factory toyota gaskets and hoses and timing belt along with alltensioners and water pump and pig tail for knock sensor. The only thing that was after market was the knock sensor. I sure will never use a non toyota part again. Hopefully this will solve my issue

James

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OEM parts are the best thing you can do for these trucks. I have heard (not seen personally) that the capacitors in the ecu will start to leak and can cause the knock code. There are two major parts the the knock circut.
1. The signal wire- you already checked this but all so verify that it is not grounded in any way.
2. The shielding - Need to verify that this is not broken and is ONLY grounded at the ecu end.

My understanding of the knock circuit is it may only output voltage when it is pinging. Unplug the sensor and run the truck. Does it still throw a code?
I found this you tube video that explains how the sensor work and how you can test them.

https://www.youtube.com/watch?v=L8xRJIWkHuo