P0300 code thrown
 

2004 S60 non-turbo. The car has been idling rough when cold but smooths out as it warms up. When it idles rough, the check engine light will come on and it's throwing the P0300 code-random misfiring. I'm suspecting a EGR valve stuck open, but wouldn't it throw a code for the EGR then?

This has also happened twice since this problem has started, but it takes a long time of cranking before the car will fire. Not sure if it's related but normally it starts perfectly but has a rough idle first thing in the morning. What could the problem be?

Could be a bad spark plug or coil pack.

Wouldn't it throw a code for a specific cylinder if it was a bad coil pack? I replaced the spark plugs and the problem remained.

Update Please?
 

Did you ever get this resolved? I seem to have very similar symptoms with a 2001 V70 non-turbo.

Thank you for your time.

???
 

update would help a lot:(

same problem
 

Do we have a solution for this item. I'm having the same problem.
Please help...

P0300
 

Possible faults for this problem; I have to check a few things
1. Fuel relay
2. Fuel pump (can be external leak) then you have the fuel smell
(can be internal leak) no smell but the fuelpressure goes away. Then it has a long cranking because of low pressure. After a few times trying to start the engine starts but runs badly...
In this last case it could be the hose inside the pump house that is leaking. Just replace that hose and it could be alright.
I will look at it this weekend. Coming back with feedback....
3. Fuelpump fail in that case change fuelpump..

tested the fuelpressure and was ok. Cleaned up the ETM and car was running fine.
Today car didn't start ok and there was the engine control light again. I wil check the sparks now....