Code P0332 Knock Sensor

Ok, I have a 2002 1500 regular cab 4.8 4L60E, ive done some search on this code already (P0332 Knock Sensor) and found out that it is the rear knock sensor if im correct, and that it can get corroded with water. Ok here was my situation. Every now and then while driving from a stop i could feel a slight surge in power but it barely registered on the tach or speedometer, you could just feel it slightly and hear it.(I already replaced plugs, wires, fuel pressure regulator, and TPS) And it was sort of isolated to damp or rainy days. So Friday night (rained all day friday) i drove to work and back home from work and then later that night i went to the bar and my SES light came on, the truck didnt run any different, in fact the surging that i felt went away. So saturday i went to advance auto and they scanned it for me and it says "P0332 knock sensor" so he looked up a knock sensor and it said dealer only part. So anyway im taking it to the dealer they are going to do it for like $200 parts labor tax. So thats worth it to me to not have to fiddle with it. So my other question is if these sensors were going bad (before the SES light came on?) would the damp or rainy weather affect them if they were corroded and send out false readings and give me my surging? And i feel i should be getting better gas mileage than 12.5 MPG. Could these sensors going bad over a longer period of time be affecting my gas mileage? And one more, i have a slight shifting problem nothing harsh or that anyone else notices but me, and people on the boards keep saying that is because my engine isnt running right for some reason, could the Knock Sensor be the culprit there as well? Thanks!

anyone? And i have noticed that since i filled up on friday right before this light came on that i have squeezed about 25-30 more miles out of the top quarter of the tank of gas. Im wondering if the knock sensor going bad has been my problem with shifting and surging and bad gas mileage all along?

anyone? And i have noticed that since i filled up on friday right before this light came on that i have squeezed about 25-30 more miles out of the top quarter of the tank of gas. Im wondering if the knock sensor going bad has been my problem with shifting and surging and bad gas mileage all along?


if the knock sensor was retarding timing this would cause all you mentioned as well as running hotter.....these sensors are to be sealed on both ends of intake manifold where i believe they are mounted on your engine, under intake , this is how they get damaged...by the lack of a good seal allowing corrosives to enter...

I havent noticed it running hottter, the temp goes up to right under 210 and stays there, its been like that since i got it in October, but if it should be running cooler maybe the sensor has been bad since i got it and just now has thrown a code. But why would i be getting better gas mileage? Im on track to get about between 500-550 miles out of my tank of 32 gallons instead of around 400.

I havent noticed it running hottter, the temp goes up to right under 210 and stays there, its been like that since i got it in October, but if it should be running cooler maybe the sensor has been bad since i got it and just now has thrown a code. But why would i be getting better gas mileage? Im on track to get about between 500-550 miles out of my tank of 32 gallons instead of around 400.

the knock sensors report to the computer if the engine is pinging if the knock sensor is not working properly it may report the engine is pinging when it actually is not this will retard timing and the spark will not occur at the proper optimal time for the most effecient operation/power.....

I would replace both knock sensors since this is not easily accessable..

Ya, im going to tell the service manager to just replace both of them while they are in there, but the thing is the up and down surging that i get while driving only happens when its wet or damp out, could that still have something to do with the knock sensor, or the wires for the sensors?

Ya, im going to tell the service manager to just replace both of them while they are in there, but the thing is the up and down surging that i get while driving only happens when its wet or damp out, could that still have something to do with the knock sensor, or the wires for the sensors?


the knock sensor produces an a/c voltage if this is varying in amplitude from max to min the timing and rpm will also vary......

But what about the fact i only notice it when its damp or raining out?

But what about the fact i only notice it when its damp or raining out?

you will have to ask MR.GM why these sensors are so sensitive to moisture..... it states in the repair manual that any moisture contact is cause for failure.....the sensors most are familar with can take all the water/ chemicals as they are on the weather exposed portions of the engine....hopefully they will install/seal these sensors properly... I would ask for a written warrantee so that they will do this correct......

ok just called the dealership and told them when i take it in tommorow that i want both replaced. i asked him about putting sealant around them and he said there is a boot around them to keep junk out, and that he only knew that cause they just did one last week. so im still going to tell them when i take it in to put some sealant anywhere where it looks like crap could get in, im also going to have them make sure the wires are still good. And get some kind of writen warranty

Ok, getting both knock sensors replaced today. Hopefully this solves alot of little problems that ive been noticing.

Ok, my truck wont be done till tommorow, they are keeping it overnight, they told me that the mechanic that was to work on it up and quit on them today, so they already had another mechanic lined up to do it first thing in the morning. Ill let you guys know how it goes tommorow.

Ok, got my truck back friday night. Oh my its like a different truck, runs better, accelerates better shifts better, better gas mileage, the whole nine yards. The tech said that when they pulled the rubber plug off the top of the knock sensor cavity that it was completely filled with water, and he showed me the sensor, it was all corroded and rusted. So they replaced both sensors and the wire pigtail, and sealed the rubber boots, so im all better and my truck is all better, thank god!

Ok, got my truck back friday night. Oh my its like a different truck, runs better, accelerates better shifts better, better gas mileage, the whole nine yards. The tech said that when they pulled the rubber plug off the top of the knock sensor cavity that it was completely filled with water, and he showed me the sensor, it was all corroded and rusted. So they replaced both sensors and the wire pigtail, and sealed the rubber boots, so im all better and my truck is all better, thank god!



thats great the truck is running normally. you should get 17-18mpg on the hwy...


how do you think water got in there????? do you put water on engine to clean it ????

No, i havent sprayed the engine down with water. I think the huge gaps in the wheel well between the inner fender and the frame lets in a whole lot of water and crap. I also had to get my hard brake lines replaced because of this same gap in the wheel well, all the water and salt and dirt and crud gets up through there and goes all over the place. So i got some rubber roofing scraps from work and im going to make some flaps to fill those gaps. Even the guy that did my brakes said the break corrosion was all because of the lack of coverage in the wheel well. So im sure the water and condensation was getting up in there as well, but i just got the truck in October and ive only put about 5,000 miles on it, so it might have been from the previous owner doing something to it, or the place i bought it (same dealership that fixed it) did powerwash the underside of the truck for me before i bought it to clean out some mud, maybe it got in there that way?

No, i havent sprayed the engine down with water. I think the huge gaps in the wheel well between the inner fender and the frame lets in a whole lot of water and crap. I also had to get my hard brake lines replaced because of this same gap in the wheel well, all the water and salt and dirt and crud gets up through there and goes all over the place. So i got some rubber roofing scraps from work and im going to make some flaps to fill those gaps. Even the guy that did my brakes said the break corrosion was all because of the lack of coverage in the wheel well. So im sure the water and condensation was getting up in there as well, but i just got the truck in October and ive only put about 5,000 miles on it, so it might have been from the previous owner doing something to it, or the place i bought it (same dealership that fixed it) did powerwash the underside of the truck for me before i bought it to clean out some mud, maybe it got in there that way?

the wheel wells can be sealed and by using rubber roofing you can keep engine compartment free from water...

when I first got my truck in 2000 i sealed the gaps with rtv and before doing this coated the metal fender portions with 3 coats of brushed on non water base sealer/sound proofing compound..


after 3years i noticed the brake lines driver side getting damaged by road spray/sand. I then used a piece of rubber roofing about 3feet long and 4 inches wide installed on engine side of plastic fender wall with washer and using 3/16in rivets to secure in place...from just forward of shock mount to mud flap behind front wheel... to date this keeps these lines and engine clean.....this done on both sides should keep all water out of engine....perhaps your sensor damage was done by car wash but using a power washer on underside of vehicle must be done with care...with my 96 impala you would never use a power washer as your opti distributor will be trashed.....

Ive got some pics of the flaps i put in, but im going to start a new thread for the pics, check it out.