I did a search and read many inputs about this P0300 Code. I still somewhat confused. I have a 99 F250 V10 SD 8800 GVWR and it throws a P0300, but never which cylinders are causing that code. I get an understanding that I can read the Pending Code and that will tell me the cylinder that is misfiring. Am I reading this right? My scanner don't read Pending Codes so I'll have to run down to Advance Auto or Autozone and get a reading. Will appreciate any info that will help me isolate the cyllinder that is misfiring..Thanks

 

How many miles on the engine? When were the plugs changed? Did you replace the COP boots at that time?

How about fuel filter - when was it replaced?

 

If it's throwing a P0300, and not a specific cylinder, it's happening all over the place, and never in only one cylinder for long.

Sounds like you might have a vacuum leak or some other reason for a totally random misfire. Check all the vacuum hoses (especially the PCV elbow) and clean the MAF, change the fuel filter (can't hurt), etc.

It's kind of amazing it's throwing a misfire code at all, given:

https://www.ford-trucks.com/forums/5...t-come-on.html

 

Thanks Krewat for your input. I went ahead and checked the vaccum lines, installed a new PVC valve when I checked the hose for leak, changed the fuel filter and cleaned the MAF. This all started when I got some bad gas. We 'snowbird' to Florida and my wife trailers my bike and I tow the 5th wheel. We both got a load of bad gas and both vehicles ran bad but hers cleared up after a couple tanks, my Ford cleared up except for this P0300 problem. I just hated to jump in and start changing coils, plugs etc until I find our what cylinder is misfiring. My scanner don't give pending codes so I'll have it checked at Autozone. The sticker under the hood says it is OBD II and complies with US and Calif requirements.