Ok this morning it was basically 0degrees Celcius (? Fahrenheit) and fired up my (2000 F150 with 5.4) truck and it started bouncing idle between 1000 and down to 400(ish) back and forth. And then very noticeable blue smoke out of the tail pipe(like the cloud out of a cold dirt bike or chainsaw in the early morning after a cold fall night), continued doing this until i idled it out to 1000 with the pedal. Once it was warmed up it had a light loping when sitting(both in and out of gear with and without brake pedal applied).

I put a new set of coils and plugs (ford oem platinums gapped correctly as well as Global COP's) over a month ago with no issues. I scanned the truck and had 4 (four) codes: P0171 - P0174 - P0156 - P0136. These codes appeared in this order, 171-174-156-136.

I have good fuel flow and pressure, truck runs great on the road as well as after it has warmed up the problem "disappears". I have been tinkering with the codes off and on and noticed that the vac line between the EVP and the EGR has next to no vacuum but good vacuum to the sensor itself. Sensor is only 60 bucks so am thinking it may be worth the effort. The other vacuum lines are measuring 18-20Hg if my memory is correct and I believe that is about right. But my memory is not the best.

I have since cleared the codes and put close to 60km's on it since and no codes yet, but am expecting to come back. Please any suggestions as to what it could be or where I should look. Uses no coolant or oil.

Thanks in advance

 

you dont have an evp(egr valve position sensor) you have a dpfe(differential pressure feedback exhaust sensor) plus i'm thinking your talking about the evr(egr valve regulator). the only time vacuum is suppose to be applied to the egr is off idle. it doesnt have have vacuum when cold, idling, or at WOT. have you checked fuel pressure before you turn the key? and while running? my old fuel pump would leak down over night and when i start it it would idle up and down a little bit until the lines had enough pressure to make it idle properly.
p0171 and 174 is usually caused by the pcv elbow on the back of the intake but you already checked vacuum right? where did you check it at?
P0136 Heated O2 Sensor Circuit Malfunction (Bank 1, Sensor 2
P0156 Heated O2 Sensor Circuit Malfunction (Bank 2, Sensor 1)
check the connections to your O2 sensors. and if they've never been replaced then they are probably ready to be replaced.

this should help you with all those codes http://www.v8sho.com/SHO/TSB0197HO2SServiceTips.htm

 

Brand new PCV from intake to valve cover, forgot to mention that. Talked to one mechanic buddy at Ford he figured to try that DPFE may also cause the smoke problem. Will look at he 02's tomorrow thanks for the replies.

 

the dpfe wont have anything to do with the smoke. all it does is read the flow of exhaust gasses going into the intake. blue smoke is oil burning. the dpfe may affect the A/F ratio and work as an input for the egr operation and turn a cel on for egr codes but thats about it. o*c is about what? like 32*f? are you sure it was blue smoke? at that temp i could see it being white smoke from moisture and the hot gasses entering the cold air.

 

Definitlely blue and definitely not oil, it was a nasty rich smell. I have an old blow thru hole in the rear wall of the cab, and the haze filled the cab. Kinda unsure about the DPFE but thinking most likely the O2's are done.

 

So finally this weekend at the lake I got it to throw the code I was hoping to see three days in a row P0401! Hoping to tackle that tomorrow and be problem free for another little while... Good ol EGR crap. Was suspicious of it but no related codes showed up.... had it figured down to the DPFE or the EGR since she runs so rich all you would need is a spark plug to make a flame thrower outta the exhaust (hahaha)