SoldierKhakiman

I recently was driving from San Angelo, Texas to Fort Hood, Texas... about a 158mile drive. While driving, my 2004 F150 FX4 started to sputter and felt as if it wanted to shut off and the Emission System Light stays on. The slower i went the less that it would sputter if any. It usually started if I went up to 70mph. Occasionally it does it at lower mph. I took it to my local auto parts store and got a diagnostic. The codes came out as P0171, P0174, P0191, P0301.

Has anyone ever had this problem before or something very similar to this???
And if so what was done to correct it?
Any help would be greatly appreciated.

Thank you,
-Josh

dplummer87

Tried posting all codes here...didnt work, posted the 4 you wanted though.

dplummer87

P0171 = System too Lean - Bank No. 1
P0174 = System Too Lean - Bank No. 2
p0191 = Engine Fuel Temperature Sensor Circuit
P0301 = Misfire Detected - Cylinders 1-10

incogmeo

Maybe this might help now that you've identified the codes.



A code P0171 may mean that one or more of the following has happened:

• The MAF (Mass Air Flow) Sensor is dirty or faulty. Note: The use of "oiled" air filter may cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicles where there is a leak of the silicone potting material used to protect the circuitry.
• There could be a vacuum leak downstream of the MAF sensor.

Possible solutions include:

• In the vast majority of cases, simply cleaning the MAF sensor does the trick. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling
• Inspect all vacuum and PCV hoses, replace if necessary
• Check for a dirty fuel filter and proper fuel pressure

Symptoms may include:

• the engine may be harder to start
• the engine may stumble / stumble, and/or hesitate
• other symptoms may also be present

Causes


A code P0301 may mean that one or more of the following has happened:

• Faulty spark plug or wire
• Faulty coil (pack)
• Faulty oxygen sensor(s)
• Faulty fuel injector
• Burned exhaust valve
• Faulty catalytic converter(s)
• Running out of fuel
• Poor compression
• Defective computer

Possible Solutions

If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.
If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.e. spark plugs). Depending on how long the ignition components have been in the vehicle, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, distributor cap, and rotor (if applicable). Otherwise, check the coils (a.k.a. coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors.


Good luck and let us know how you resolve it ... heres the link to where this info came from http://www.obd-codes.com/trouble_codes/

Cog

dplummer87

I thought a lot of it sounded like bad spark plugs/wires or even distributor....But if it is running lean, that could gum up the spark plugs which would cause the other codes etc...chain reaction...hope that info helps man.

SoldierKhakiman

Thanks to those who have replied. Hopefully it is just sparks. Ha

cchanderson

Hey Soilder...if you have coil packs dont take it in they'll rape you. When I have a "coil pack" or "coil over plug" go bad its less noticable at higher rpms than it is at lower rpm's. Each one of your eight plugs has one on top. I think they are suppose to be rated at 100,000 miles but through some of my reasearch ive found they usually dont last near that long due to moisture problems.

Ive tried all brands but find the cheapest from Autozone for 65 bucks last just as long as the NAPA ones that are 85$. If your plugs havent been replaced in a long time this is a great time to do that as well.

Basically what I do is run a diagnostic and get the cylinder #. Then go buy a coil, take off one screw, unplug it gently so u dont pull out the wires, pull out the old coil (sometimes the boot stays in the hole no worries just pull it out with needle nose pliers). Then apply the silicone greese that comes with the new coil, (put the rubber boot on and squirt it into the opening). This is important and what the Ford Mechanic did not do when I took it in to get serviced (but im sure most do). This is why many think they go bad so often. Then reseat the new coil...you'll feel a little pop when it pops over the plug....reconnect the wire and screw down the new coil.

Thats it....I did one 3 weeks ago and it took me 15 minutes...I have an 01' I am not 100% sure if you have this set up but if you do...that is how u do it.

rcardell

the p0171 and p0174 are lean codes the p0191 is a fuel rail pressure sensor code and the p0301 is a misfire on the number 1 cyclinder,with out doing the proper diag theres not a lot you can do but through parts at it,but starting with the 301 code this code be a bad spark plug or a ign coil or a injector but most likely a ign coil,number one is the first one on the right side the best way for you to test it is swap it with the one next to it and see if the code changes say if you swap it to number 2 the code will change to a 302 if it does then you know the coil is bad,this misfire can cause the lean codes but the fuelrail sensor could also cause the lean codes,if you dont want to go that route i suggest taking it to a ford dealer and let them do a proper diag it might save you some money in the long run,i know because i do driveibility work at a ford dealership have worked at a ford dealership for 40 years i know its hard to spend the money i know i couldnt aford most dealers prices!hope this helps

rcardell

the p0171 and p0174 are lean codes the p0191 is a fuel rail pressure sensor code and the p0301 is a misfire on the number 1 cyclinder,with out doing the proper diag theres not a lot you can do but through parts at it,but starting with the 301 code this code be a bad spark plug or a ign coil or a injector but most likely a ign coil,number one is the first one on the right side the best way for you to test it is swap it with the one next to it and see if the code changes say if you swap it to number 2 the code will change to a 302 if it does then you know the coil is bad,this misfire can cause the lean codes but the fuelrail sensor could also cause the lean codes,if you dont want to go that route i suggest taking it to a ford dealer and let them do a proper diag it might save you some money in the long run,i know because i do driveibility work at a ford dealership have worked at a ford dealership for 40 years i know its hard to spend the money i know i couldnt aford most dealers prices!hope this helps