96 850 Turbo 96K
On OBD II:

P0326 Knock sensor 1 circuit range/performance
P1310 Manufacturer control ignition system or misfire
P0301 Cylinder 1 misfire detected

Symptoms are loss of power and poor excelleration

Spark plugs changed by ind volvo shop at 90K scheduled maint 4k ago

A few weeks ago, the only code was P0301. This afternoon, I picked up the knock sensor kit from the local dealer with the intent of installing before seeing these additional codes AND learning that the intake manifold must be removed to get to the sensors. So, before investing more time and money, I would like to be sure that the knock sensors really are the culprit and really need to be replaced.

1. Is there a way to further troubleshoot the sensors? (The 700/900 FAQs suggest that the OBD codes is the only way to know if the sensor is bad.)
2. Could a bad plug or plug wire cause all threee of these three error codes?
3. If I remove the intake manifold, should I plan to replace the gasket, seals, and FI O Rings upon reassembly as the Haynes manual suggests? (Don't know anything about gaskets - AutoZone says they carry Fel-Pro who doesn't make one for this car - do I have to get one from Volvo?)
4. I don't own a torque wrench and see it is recommended for both spark plugs and reassembly of the intake manifold. What kind of wrench(es) do you recommend and where to buy? I see them carried by both Wal-Mart and Sears.
5. If the answer really is to replace the sensors, please provide hints, tips , or advice about removing and replacing the intake manifold as this seems a little daunting to me.

Please help with this as I know just enough to be dangerous and don't want to be wasting a lot of time and money unecessarily. I will look forward to your responses.

Regards,

Calvin
96 850 Turbo 96K
92 940 196K