So as I'm driving to college today my CEL starts to flash (it's been on cause of misfire cyl3 which I replaced) so I know from experience that it flash before it throws codes so I didn't study it a whole lot but I noticed loss of power lack of throttle response etc so after class I take ol girl to oreillys to get her scanned 5 codes in total
P303 misfire in cyl 3 which I replaced
P0172 system to rich
P0300 multiple misfires
P0307 misfire cyl 7 haven't replaced yet
P0357 I think is what it was which is bad ignition coil

Trucks an 05 KR 4x4 Replaced coils and plugs in cylinders 1-4 and 6 so I still gotta do 5,7,& 8 anyway I need help any help as to what to do besides change plugs and coils how do I test coils and what not how do I fix the system to rich?

Thanks Forrest

 

The answer to all those codes is - change the plugs and coils!

 

KingRanch, I removed the other thread in the 04-08 forum that you started on this problem. Please don't create multiple posts on the same topic - it can lead to confusing responses. Follow glc's advice - he knows what he's talking about.

- Jack

 

Yep replace coils and I would do all plugs and if cylinder 3 comes back put your finger on injector should almost feel like a pulse. What kind of plug/coil did you use as for running rich emission system will be picking up the un-burnt fuel being put through it. Don't run it to long or your catalytic converter will go and they are expensive. Also 05 were bad for injector problems

 

Its an 05. Injectors. one is stuck system to rich. Probably does need a tune up but I'd check the injectors. Fact is if I owned an 05 I'd change the injectors out before the warranty expired.

 

Well I got rid of the codes except the P0172 so it's either injector or O2 sensor how do I check those two things

 

I was gettin po171. Check your pcv system.

 

its a vacuum leak.

 

How do I check for it

 

No, a P0172 is rich, not lean. Most likely a leaky injector. If it has less than 120k miles, Ford will replace leaky injectors on the house.

 

thats right! I was thinking 171/174 it is an injector!

 

stop throwing parts at it why don't you diagnose it codes are not their to tell you what part to replace.

 

Who is "throwing parts at it"? Spark plugs are a normal maintenance item and coils don't last forever. All the codes are now clear except for a P0172. The 05 5.4 had a known bad batch of fuel injectors that stick open and we are suggesting that THIS is now what needs to be checked out. A P0172 is consistent with this and Ford has extended the warranty on the injectors to 11 years/120k miles. Replacing ALL the injectors with the improved ones is actually a good way to go for the long haul. Ford will only replace the ones that actually test bad.

 

your spot on I said that because I read in the posters write up he already replaced the coils. how ever replacing fuel injectors is usually a benefit you can also say that about the pcm egr and anything else you can buy at a parts store. If its not broke don't fix it you can also get bad parts that would add to confusion. but looking in to testing fuel injectors is a great idea I just was saying that part replacement can and will lead to lots of frustration.

 

The injectors from the 05 MY are known to fail. There is a 120k 11 year coverage extension provided by ford but if I had an 05 with those injectors I'm replacing them before that coverage expires.