Repetitive Knock Sensor Code - '94 850 T5

[donis222]

My 94 850 turbo was throwing codes. This was with the new sensors. I checked the #2 sensor from the front by removing the starter. The sensor was good, the adapter wiring connections were dirty. Clean them and fixed.

[VolvoBug850]

1996 Volvo 854 Turbo - So this code is creeping back into my car again, 16 months with no problems and being able to run the car hard whenever I wanted to. This time around it is P0331 - Knock Sensore Bay 2 (last time was Bay 1).

Anybody know how to test the updated knock sensor kit? I can only find data online how to test the old kit, before the replacement parts. I would like to do an Ohm test, or whatever is required, before tearing into the car.

Last time I fixed the issue by buying a new ECU - the Volvo dealer said "all options were exhausted, ECU is fried" and tried to sell me one for $400. I got one for $75 from a Volvo parts place near Denver. Has worked beautifully ever since popping that ECU in.

Hard to believe the brand new updated knock sensor kit would die within a year, when the factory ones lasted 12+ years??

I did the updated knock sensor kit from FCP Euro 16 months ago, where you splice the wires and build the connectors on your own and all of that stuff. Since this CEL on Friday, I put in a bottle of octane booster, and then filled up with a different brand 93 octane fuel (Phillips 66 this time, citgo last time). I ran the car for a while, maybe 5 miles, and then 10 mins at idle. Cleared the code, started it back up - CEL back on within a few seconds of running.

From reading above posts, I feel as though it could be the wiring, someone said it is the wiring if the CEL isn't set under WOT or heavy throttle. I was just cruising along the highway, 65mph, cruise control and the code came on - car started running like garbage again (limp mode?).

Any information would be greatly appreciated, or Volvo service documents, anything. I can't seem to find any data on this updated knock sensor kit, it is like they came out with a fix for it, but with no supported documentation (other than the install service bulletin)