Engine codes PO300 & PO304

[Flydog]

I have a 2002 Explorer, V8 and on a trip out of state a few days ago the check engine light came on. It has a miss and the fuel miles per gallon went down. Normally I get anywhere from 17 mpg to 19 mpg combined city and highway driving. I was pulling a 17 ft boat and the trip was about 300 miles each way. My gas mileage dropped to as low as into the 12's and ranged up to the 14's. Now that I am back home and not towing anything my mpg has went up into the 16's.

My check engine light came on and was flashing during the trip and after I got home it quit flashing and now stays on constantly. I had the engine codes pulled at Autozone and I got codes PO300, PO304 and PO316. Also the guy at Autozone said the code checker showed my miss to be on cylinder # 4. My plan is to check the spark plug and coil on cylinder # 4.

Has anyone else had a similar problem with a single cylinder seeming to be the source of the miss ? If so what was the problem and solution.

Also does anyone have any suggestions other than the coil / plug ?

Thanks,

Flydog

 

[CasterTroy]

Also does anyone have any suggestions other than the coil / plug ?

Thanks,

Flydog

Any updates? Any solutions?

Same problem. Flash at Auto Zone said PO316 and the other was for cylinder # 8

158K plugs replaced at 100K Coil pack 8 was replaced last night. Now check engine light flashes and hesitation under 1500 rpms. Auto Zone OBD said possibly cam position sensor

 

[rocco123]

U sure the plugs are all tight? She may be getting ready to spit out a plug. Been there.