OK car set for a good while, as I searched and searched for a persistent coolant leak. Ended up replacing a year old water pump and leak has ceased. Car was started regularly and driven around the block just to spin tires while down but that was it. Never had any issues during this time. After replacing water pump I started up the car and sprayed down the front end to clean up any spilled coolant. Immediately I started getting restricted performance. I've pulled codes and it's consistently P0328. I could hear a knock here and there, but have since had the oil changed, added a bottle of SeaFoam, run the old gas and refilled tank. I've pulled both sensors, cleaned and replaced, I even installed new plugs. I've got a whine in the serpentine belt but other than that, no knock. Despite these measures, I'm still getting a intermittent restricted performance. Sometimes I get the message and then it disappears without causing the Check Engine light to come on. Other times I've got the check engine light and no restricted performance, but the code is always the same, occasionally I get a 1642(Can Failure) but only once or twice. Is this a bad sensor or possibly something else.

 

Not a great idea.

Check the connectors for the knock sensor leads. The leads run forward from the sensors.

 

As plums said, the connectors for the knock sensors can get wet (they mount on the thermostat riser on a NA), but the sensors housings themselves crack and allow water in. Look to the archives for knock sensor replacement.

The CAN bus fault is more than likely an artifact of connecting your scanner.

 

I just went thru the same situation with mine. I cleaned the front of the engine and got the same code. I cleared and reset and all was good. But like they said check the connections which I did and blow away all or most of the water and just let it dry out and try it again. I learned my lesson on washing this motor.

 

Ive had both knock sensors off the car, shot all connections with connection cleaner, checked wires, and bolt down locations. I'm beginning to think the drivers side VVT sensor got a bit gummed up. I did a full Timing Component rebuild about 2 years ago. Latest upgrades on all parts. I noticed a slight ticking on drivers side after I'd let off the throttle, similar to a bad tensioner but not the same. I found a thread in a broad Google search that ID'd a lot of same issues with a blocked port in the VVT sensor (makes sense oil could have gummed it up). I did a full oil change first few days into the problem and added a QT of Seafoam to clean things out. Thread I found said to use ATF or run some diesel oil to clear it out. I added about a pint of ATF first of the week and haven't had any issues since.