2005 Honda Accord

At 59,400 kms my check engine light came on. Dealer checked and found codes p0301 (#1 misfire) p0305 (#5 misfire) p0300 (random misfire). Dealer cleared codes and checked all fuel trim parameters with HDS and everything is ok. Road tested and everything was good. Suggested intermittent failure
At 61,510 kms CEL came on again. Dealer checked and found 1 DTC-p0325 knock sensor 1 no signal. Dealer inspected circuit as per svc manual, no faults found. Checked freeze frame data for abnormal conditions and all parameters looked ok. Set at 50kmh/3284RPM. Fuel trim OK, O2 sensor values good. Fuel level 44%. Cleared code, ran vehicle to operating temp and ran check as per svc manual with no knock sensor faults present. Advised this is an intermittent fault and all OPs ok. Also during diagnosis checked for misfires and no misfires present.
At 62000 kms CEL came on again and stayed on for a day and then went off for no apparent reason. Stayed off for a day and is now back on again. Each diagnostic is costing me $122 so I am looking for suggestions. Car continues to run just fine. Have done the gas cap thing and switched service stations. Any help would be appreciated.
October 24, 2007.

Misfires can be caused by worn or fouled spark plugs, a weak spark (weak coil, bad spark plug wire), loss of compression, vacuum leaks, anything that causes an unusually lean fuel mixture (lean misfire), an EGR valve that is stuck open, dirty fuel injectors, low fuel pressure, or even bad fuel.

A Random Misfire code P0300 usually indicates a vacuum leak or bad gas.

If a misfire in a specific cylinder should lead you to check the spark plug, fuel injector and compression.

Oct 24, 2007.
Thanks razmataz. On the first occasion, (misfires) after the diagnostic test and reset, mechanic said that there was nothing wrong other than intermittent fault. Same thing after the second diagnostic a week later regarding the knock sensor. I was told that the second incident had nothing to do with the first. Is it a matter of replacing parts until CEL light doesnt come on any more?

Oct 25, 2007.
Well, honestly I believe you're dealing with partschangers go somewhere else. They just milking you little by little till its gone.

Oct 26, 2007.