Ok so the other day the truck started smoking excessively (white smoke) mostly just when cold.. I didn't think a whole lot of it because I figured injector stiction. (The truck has 160,000 mi on it). There was not a noticeable miss while idling though. Last night I was driving and started to get an unresponsive throttle and it continues today after its warmed up. It does it when its cold also. Got a CEL today and went to Autozone for the code read. U1900, P0528 & P0404
P0404 EGR valve
P0528 Fan speed sensor
U1900 ???


Im going to look at EGR valve here shortly and clean it try to get it functional again but I think it is coincidental and it doesn't have anything to do with the throttle issue...Help please

 

I'd inspect and clean up the fan connector first. The wires go up under the fuel filter/regulator housing be sure to look for abrasions on the insulation and corroded pins in the connector at the fan shroud. If it's still messing up after that I'd try unplugging the Exhaust Back Pressure sensor (EBP) and driving it a little. The EBP sensor is located on the end of a hard tube coming from the drivers side exhaust manifold. When you unplug it, protect the connector on the end of the wire from touching anything while its disconnected. (Zip tie it to something)

The smoking may or may not be related to the dead pedal. Try to get a wiff of the smoke to see if it smells like fuel or anti-freeze. Inspect in the intake manifold for wetness under the EGR valve when you pull it out. It may be shiny or a bit oily in there but shouldn't be wet.

 

Thanks Rusty. Im on it. Im trying to get the EGR valve out now. One of the darn bolts is trying real hard to round off. They don't make Craftsman sockets like they use to.

 

No doubt. I've been buying Colbalt stuff from Lowes the last few years. Kinda hit and miss on what's good. I do know their thinwall impact sockets can't hack it. 6point stuff is you friend.

 

Even the 6 point failed. Rounded the bolt right off. I was able to get a tool to get on the bolt and it worked thankfully. I was not looking forward to drilling the bolt out. Ive seen that turn into a nightmare before.

 

DOH!!! Got it off and cleaned up. Throttle response is back to normal. So that's why you need to clean the EGR valve on these trucks regularly....LOL!!

 

Well the valve cleaning lasted a day. New valve @ autozone 109.99. I unplugged the valve and end of throttle problem. From what ive read, cant I just leave the valve unplugged? I know I will have a CEL light unless I install a programmer. How do these EGR valves work?

 

Depending on the PCM flash version in your truck, leaving it unplugged can cause problems with the cooling fan clutch operation. Apparently the feedback from the EGR valve (along with other inputs) is used to compute fan speed.

https://www.ford-trucks.com/forums/9...egr-valve.html

 

Thanks. Im wondering how to know whether or not I have that flash.

 

KBF, you EGR valve looked "wet" if that is the case you likely have a leaking EGR cooler..
Maybe you have a carbon 'marble' that gets your EGR valve stuck.. that is also a symptom of an EGR cooler leak, a post last week went from a stuck EGR valve to a blown EGR cooler inside a few days... with a LOT of white steam out the exhaust..
https://www.ford-trucks.com/forums/1...r-marbles.html

I think by 2006 all the flashes use the EGR to control fan speed.

 

Thanks. I didn't see any signs of moisture when I looked inside the intake.

 

For a device that is only there to control nox emmissions it shure causes a lot of problems when it doesn't work right.