P0333 Knock Sensor Code

So yesterday my check engine light comes on. 2007 4.0. The code is P0333 Bank 2 Knock Sensor. It went off, then came back on today.

Couple things:

1. I've heard this is usually due to a rodent chewing the wire and it's a bitch to access requiring intake removal, etc. I am super busy at work so that means $$ at the shop.

2. This happened Friday morning. Thursday evening I had JUST filled up at a shitty looking gas station I had never been to before. All that was around...I know. Coincidence? Could it be bad gas actually causing knock? I have half a tank left. Should I run it to almost empty and fill up with good stuff and see if that fixes it? Is this a possibility or am I a delusional optimist?

Anyone deal with this?

 

Unfortunately the chance of it being the gas is slim to none. Rodents can't get enough of the wires down there. I've replaced a ton of knock sensor harnesses. I'd try to take care of the rodent issue first because they will just keep coming back.

 

It could be the wires but it's quite possible the sensor could just be bad as well. I don't know if it is common in these trucks but this is very common on the Chevy 5.3 because the way the manifold sits allows water in and so they get water in there and the sensor goes bad. If you're gonna open it up just replace the sensor too so that you don't have to worry about it anymore

 

Once you get in and see the design of the heads(how the intake ports are) you might think twice about replacing the sensors while you are there. They are a real pita. For a customer, it would be doing a thorough job, on my own car . . . Uh maybe next time (as long as you actually see the rodent damage). Besides the manifold comes off in 15-20 minutes

 

Here's a pic not meant to scare you sense it's not really necessary but . . .

 

Check engine light is back off today. That makes me think it's not the wire? It seems it would be lit up steady if it was, right?

I filled up at a trusted station today. Guess I'll watch it this week and see what it does. CEL came on Friday for the first time, and it's been off more than on sense them. Maybe 30% on and 70% off. Maybe faulty sensor or it's actually working correctly and picking something up?

When the CEL is on I can feel "safe mode" kick in which is less than ideal.

 

just keep an eye on it

 

Will do. If it doesn't go away in a week it goes to the shop. Seems like it could be a tricky thing to diagnose for the inexperienced like me. Maybe it actually has a detonation issue? I have actually thought I noticed slight spark knock while going up hills occasionally for a long time. And it's hotter than hell here now. Bad gas+heat+carbon+ 230K miles might make for that?

 

I have had a po333 sensor code for the last 4 months. now it's cold weather the code will clear out and not come back for now. Think its just a loose connection that comes loose with heat or did I get bad gas? Took It to the emissions station and it passed no problem. Before I would get about a mile from the Emissions and the light would come on.

 

I found that clearing the Maintenance light 3 times in a row will clear out the check engine light.

 

Rodent got to my knock sensor, cost $3,600 to replace. Insurance covered all but $100 deductible and $39 for 1 week of rental car.