Help! Confused???? Fault code P0305
 

Hey everyone, I have searched my problem to no end today and can't seem to make sense of what is going on.

My rover sat for about a week with varying weather 10 degrees at night, highs in the 40's.

It is a 2000 D2, 115k miles

Rotella 15w40 oil, mobile 1 filter

New oem air filter, always 93 octane, Seafoam in gas tank every 3-4 months.

I had the P0305 code with flashing CEL every once in a while at stoplight, so I replaced plugs with Bosch and wires stock because of time. Shop I trust did wires because I am a wimp and don't have a garage at the moment. Got Rover back, no codes took off like a rocket, no issues. I put about 30miles on it and one morning the CEL came back on, then started flashing at stoplight every so often. I went to Autozone and had it scanned and it came back as P0305. I had talked to a guy near me who uses the same gas station I do. About the same time I filled up, he did and had bad gas in his car. Not sure if this may be part of it, but worth mentioning, I was down to a half a tank, so I filled up with Seafoam and went on a 70 mile drive CEL is on, but runs perfect and no flashing at all.

What should I do next? Could it be an O2 sensor or a Coil Pack?

When they have scanned the rover for the codes, it was not running, should I just go buy or rent a scanner and scan it while running/driving to get better data?

Could it be as silly as a new gas cap?

It runs really strong, so I really doubt it is the sleeve issue.


Thanks for any help you guys can give me.

Andy

Bad gas would throw misfires on all cylinders, not just one.

Just follow the crowd and get your coolant system pressure tested..

Who's wires did the shop install? Possible loose connection, cracked plug, burned valves or a flat lobe on the cam is starting to show up.
I would take it back to the shop that did the work.

Shop put napa wires on it. Did some of the rest of the major service and ran it a little more. I ended up pulling the codes again to find that I have the multiple misfire code along with the P0307. I pulled the plugs and they normal, no steam cleaning or soaked in wet black oil.

I checked the plugs on the coil and they were seated properly.

As a follow up, the engine light went off and has stayed off. I check the oil every week, it looks normal. No Coolant leaks and no drop in the overflow. The coolant has not changed colors either.

I am going to be changing the valve cover gaskets hen the weather finally hits 80 degrees here, but as for the previous CEL, I am stumped.