2002 F150 Codes P0303, P0316, and P0171
 

:-huh:confused:The issue started about three days ago with a slight hesitation and bumpy acceleration. The check engine light came on and then went off. The vibrations have been getting worse at idle but are smooth sometimes as well. I went to the auto parts store and had them scan for codes and I received codes P0303, P0316, and P0171. Does anyone have any suggestions? I added some Lucas injetion cleaner, and am going to install a new fuel filter, and spark plugs tommorrow. Am I on the right track or should I be looking somewhere else??? Any help would be greatly appreciated. Thank You!<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p>
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:-huh

P0303 is a misfire detected in cylinder 3. P0171 is system too lean, bank 1. I don't know what P0316 is. It might be a generic code that covers multiple symptoms. Try using your computer search engine. I did that with an unknown code I got with known codes and it turned out to be a generic catch all code.

Whimsey

Autozone says that the P0316 means a Crank Sensor Condition. I have also seen on this site that it means Engine Misfire Detected on Startup (First 1000 Revolutions). I am not sure which is correct. Does anyone know the correct definition???:-huh

My scanner interprets it as "means Engine Misfire Detected on Startup (First 1000 Revolutions)"

I am troubleshooting the same codes (different cylinder PO301, which is more covienent) replaced the spark plug and it went away for 15 miles, now back with PO301 and PO316 again...

Next work is Coil Pack, then Fuel Filter, if that doesn't solve it. Let me know what you find, and I will do the same!

What I found
 

Chad,

I went ahead and changed all 8 spark plugs since I had about 94,000 miles on the truck and they are recommended @ 100k. The spark plug on cylinder 3 was definetly fouled. I also found that the coil pack on this cylinder was bad. After changing all this as well as the fuel filter my problems went away. I hope this helps you. Good luck!:-drink

Troubleshooting Bad Coil Pack
 

How did you determine that the Coil Pack was really bad? Or did you just assume like I am that becasue the code was for that cylinder, it had to be bad?

I have 108K on the truck so I think I will replace all the plugs as well...

Too bad #4 and #8 are so far back in there :>

Chad

More Codes
 

We had some serious rain here today and my 02 F150 supercrew 5.4L Was doing fine until finally this one flooded area. It started running really rough and then the SES light came on. I am used to the rough part since I have a COP that occationally acts up and doesn't come on. Well now it is off for good. I had Autozone pull the codes and it hit P0305 and 0316 Basically, #5 COP and it says Crank sensor condition. Crank sensor defective? I was able to quickly replace the #5 COP but my SES light is still on. Does it reset after a while, or should I disconnect the battery for 10 minutes or so and then see if the crank sensor corrects itself and the SES light stays off? Thanks.

I had the same errors, changed out the COP and reset the codes. It has been running fine for 2000 miles with no returning codes. The code should go away after a while but can Autozone reset it for you?

I just unhooked my battery and it reset the light, driven for 3 days and actually runs better than before. I have had a COP acting up for about 2 years but every time I take it in they cannot find the one that was acting up. It never kicked the SES light so it was intermitten. Thank you for your response.