Well I just replaced the crankshaft position sensor after it totally cut off at 45 mph. Drove fine and smooth after replacing cps. Stopped to get gas. Left the gas station and the check engine light started flashing and riding rough. Went from flashing to just lit. Checked the code p0303 which says a misfire in cylinder 3. No coolant in the oil. Not blowing one bit of smoke. Any suggestions. I’m messing with it tomorrow

 

Try swapping spark plugs and see if the cylinder changes? If not, ideally, next swap plug wires, but they aren’t easy to access on the coil end.

 

Do you notice a misfire or does it run smoothly but still generate a code?

 

I will try that tomorrow and hope that can help narrow down what’s happening. Thanks

 

It was running smooth as glass then I got gas and then rough at idle as well as in motion. Also big loss of power.
maybe bad gas?

 

Could be bad gas, but it would usually have multiple misfires.

 

I’m convinced I’ve had a couple of bad batches of fuel in my life. For a whole tank of gas the engine just didn’t run quite right. I haven’t noticed this in years though.

 

I had one tank of bad gas after Hurricane Harvey. 99 D2 cranked up and the sputtered. When I gave it gas I got a flashing CEL, and I quickly pulled the codes. I had multiple misfires. I restarted it, and it ran but wasn't perfect. I didn't get a full tank of fuel so I went home and added a fresh 5 gallons to it and that made it run better and the flashing CEL and faults never returned after that.

 

I’m hoping that would be the case. It happened the immediately after getting a few gallons. I usually get non-ethanol 93. So that’s what I’m going to try 1st

 

Well….. filled it up when non ethanol 93, seafoam, and octane booster. Still misfire number 3. Changed plugs. Same. Even used a camera to look inside where the plugs reside to try and find evidence of anything. They all looked fine. Looking to order a kit to relocate the coils. Unplug old and reroute to desired location. To be continued.