04 Screw P0325 P0330 knock sensors

[vandj12]

Well I'm stumped. After weeks of digging for info, the CEL on my 04 Screw 5.4L 3v was showing DTC P0330. Dealership wanted ~700 bucks to change out both knock sensors as they were sure this was the problem. Truck was hesitating when under load or at higher RPM. After several code clearings at the dealer code kept coming back within the 1st re-learning drive cycle any time it was under load. I spent the time and money to change out both knock sensors myself and bought a scantool to be able to read and clear myself as well. All was fine for first 80 miles or so driving cautiously at low rpms. First time I got on it a little the CEL came back on and this time I've got a P0325 which is the opposite bank sensor. When removing old sensors, passenger side sensor did have some exposed copper on lead where it had possibly been rubbed through and grounded to the valve cover so I assumed I had found the culprit. I'm thinking next to check would be ECM but I've also heard the COP's could cause something like this. Anybody with similar issues who might know something would be greatly appreciated. Oh by the way truck has 40000 miles on it, just enough to be out of warranty wouldn't ya know.

[royb]

it's not the cpu it's most likely the wiring got smashed in between the engine block & firewall. You can diable the knowck sensors with the correct software package (SCT come to mind) - heck you can remove them and still get by. the downside is if you run bad gas and the knock sensors pick up knock it won't remove timing when needed. if your truck is not modified you really don't need them as long as you have good quality gasoline.

[fishel74]

What do you mean by SCT. I have a 2002 5.4 that has the code p0325. I only have one knock sensor. How can i disable it, the engine is fairly stock with a cat back exhause and k&n filter.

[VFR_Man]

I would also check the fuel pressure if you're running out of ideas. A weak fuel pump can cause the symptoms you described; runs like hell under load/high rpm, but runs fine just poking along.

[royb]

Originally Posted by fishel74

What do you mean by SCT. I have a 2002 5.4 that has the code p0325. I only have one knock sensor. How can i disable it, the engine is fairly stock with a cat back exhause and k&n filter.

you will need a flash programmer SCT is the company SCT Automotive Performance Products

[royb]

Originally Posted by vandj12

Well I'm stumped. After weeks of digging for info, the CEL on my 04 Screw 5.4L 3v was showing DTC P0330. Dealership wanted ~700 bucks to change out both knock sensors as they were sure this was the problem. Truck was hesitating when under load or at higher RPM. After several code clearings at the dealer code kept coming back within the 1st re-learning drive cycle any time it was under load. I spent the time and money to change out both knock sensors myself and bought a scantool to be able to read and clear myself as well. All was fine for first 80 miles or so driving cautiously at low rpms. First time I got on it a little the CEL came back on and this time I've got a P0325 which is the opposite bank sensor. When removing old sensors, passenger side sensor did have some exposed copper on lead where it had possibly been rubbed through and grounded to the valve cover so I assumed I had found the culprit. I'm thinking next to check would be ECM but I've also heard the COP's could cause something like this. Anybody with similar issues who might know something would be greatly appreciated. Oh by the way truck has 40000 miles on it, just enough to be out of warranty wouldn't ya know.

I would replace the wire harness that goes to the knock sensors providing you already put new knock sensors in. If that doesn't clear the code then your next thing is to check the MAF & you can do that by datalogging the truck and check your STFT & LTFT (short & long term fuel trims). if htey are off you recalibrate the maf.