2003 4runner - Knock Sensor P0330

2003 4runner V6 SR5, 191,000 miles
Bought brand new in 03'. Only driven locally now, put about 5000 miles a year.

Engine light turned on a couple of weeks ago, ran 1st scan at Autozone and came back as a Knock Sensor P0330 Bank 2. The next day, the engine light turned off but the VSC/Trac lights stayed on. I tried to do a zero point reset but the VSC/Trac lights always came back on. Parked for a week to go on vacation. After returning, engine light came back on. The same code came back and again after a day the engine light turned off.

Took it to my local trusted mechanic. They said it is intermittently throwing the code. Their recommendation is to keep driving the car with light going on and off until I start having drivability problems. Which I don't right now. Estimated cost would be $3000 in labor and additional what ever else needs to be replaced or breaks in the process of getting to the sensor. So I am guessing $4000-5000. If I had to bet, my guess it is not the sensor but the wiring.

I know it is a P.I.A to get to the senor and wiring. Does anyone have any history of driving with the engine light on for the knock sensor for a significant period of time? Is there anyway to circumvent the computer telling the engine there is something wrong? It's getting hard to justify putting so much money into a car that probably on worth $1000.

 

Don't quote me but i believe the knock sensor just adjusts timing if it senses pre-detonation. If you are just 'putzing' around town i doubt you'll get into a knock type situation. From my understanding knock occurs mostly under heavy load or high rpms. Could just keep driving it with the lights on. Only problem is that may mask other potential issues that pop up, since your CEL will already be on and you'll be thinking its for this knock sensor issue.

I also can't believe a $3k quote, even if it is hard to get to. Maybe they are pricing in a ton of 'assumptions' and be conservative.

 

That price point is the "i dont wanna fix it, so here is a ridiculous price for me to have to spend my time chasing down a rabbit"
When the ECU sees knock, it changes the timing and fueling tables to try to "reduce" the knock. If after it changes the tables and the knock goes away, the ECU will roll back into power. If knock reappears it will do the cycle again to reduce knock. If this happens a set amount of times and the knock doesnt go away the ECU will trigger the light.
THE OTHER REASON the ECU will trigger the light is if there is a grounding issue, which i would most highly suspect is your case. I suspect you have a wiring issue, the sensor is getting intermittently grounded from a wire rubbing ground (engine) or a rodent has chewed thru the wiring and the wires are touching other exposed wires. This means you could need an engine harness, or if the chewed thru area is easy to find you might be able to doctor the wiring up and fix it for little to no money. How much stuff you have to pull off, to find the wiring issue, is what is the big what-if. You might be able to find it in a half hour, you might spend two days chasing your tail and have the whole engine harness removed and still cant find anything wrong.

My first thing would be to replace the sensor and look for wiring issues with what you pull apart and continue to drive it.
If the CEL comes back after sensor change then you most likely have a wiring harness problem. Then you most likely need to pull a lot more stuff apart and find the wiring issue.

 

Where are you located? What color is your unit? If you cant fix the problem easily and your bottom dollar is as low as you think it is, i might be willing to buy it. My daughter just turned 15 and i've been looking for a vehicle to put her in.

 

Thanks for the info! Yeah I think I am going to keep driving it and see what happens and also just keep scanning for other codes. The book time for the work from Toyota is 16 hours! I think the price, has to do with them not really wanting to take the engine apart to figure out the reason for the light. Which I don't blame them.

 

Thanks for the great information. I 100% agree, the price is the "I don't want to go in to that rabbit hole unless you want to pay alot of money" There is a local guy that only does engine work, I may have him take a look down the road.

I had my brother reach out with the same question regarding selling the car for his 15 year old daughter. I would not feel safe for her driving it. It has lived one block from the ocean for 20 years. Sunroof is completely rusted out, back hatch is rusting from the inside out. Anytime I try to fix one thing, 3 other things break. We are in the "lets drive it to the wheels fall off" era. But I would love to get another 5-10 years out of it.

 

Here is the video how to do it in 48 minutes without pulling the heads. Notice when he gets down to the knock sensor there is a mouse nest in there, which is likely what happened to you and you have had a critter chewing on the wires.

https://www.youtube.com/watch?v=hwVcU7mkap4