CODES P0206 P0306
My wife's 2017 Ford Explorer 3.5 V6 mileage 144,000 majority were highway miles. One owner, bought it new and well maintained, no issues except for the very expensive water pump replacement which even though being a mechanic my entire life I just didn't want to tackle that one. Recently check engine light came on so I looked at the codes "P0206 Injector circuit/open cylinder 6" and "P0306 Cylinder 6 misfire detected". I swapped coils from cylinder #5 but the codes still remain for #6. I put a new spark plug in #6 but no change. When the check engine light is on and blinking the engine has a noticeable miss. After you drive about 5 miles the check engine light goes from blinking to on solid and then it runs just fine with no miss. Bad injector? But if so why would it run fine after the light goes solid? Can the fuel rail be lifted high enough to change injectors on the left bank (front) to change an injector? I know I have to remove the upper plenum and several other hoses and brackets to change anything on the right bank (rear of engine compartment) Today I drove about 45 miles. The first 6 miles flashing light and bad miss, then light went solid and ran fine. I made three stops of about 15 minutes each and each time I shut off the engine and each time on restart the light came on solid and car ran fine. Thanks for any advice or assistance.

 

Any opinions? Have any of you experienced a similar problem? I'm still leaning towards changing that one injector but wondering why it alternately has a miss and then it doesn't. Could it be an electrical issue with the injector itself that prevents it working when cold but as the engine warms up it then works as it should. When she came home from work today the engine was warm and the check engine light was solid. We ran several errands, drove 10 miles, stopped for an hour or so and then home and other than the light being on the car ran perfectly.

 

Well I changed the injector on cylinder #6 and installed a new Motorcraft CM-5188 injector and it seems to have taken care of the problem. Even though I had no replies to my initial post I thought I would post an update should any of you have the same issue as I did.

 

Why, being a mechanic, did you decide to swap coils/replace a spark plug for an INJECTOR CIRCUIT code?

 

Because the first code I got was #6 misfire. The second code didn't show up at first. I should have explained the sequence of the codes.