EGR Unpluged

[sthomps]

I was just wondering if anyone might know why a CEL will come on when the EGR is unpluged on the 05 and newer 6.0L. I realize that the computer is getting a voltage out of the correct parameters. But what if the EGR hole is pluged and the EGR is left pluged in?

[SCUFFY828]

unplugging the egr will on any model turn the light on, without custom tunes you cant fix that ,if the hole is plugged and the egr is left plugged in if its a bad egr valve , it still may throw a code , what code /codes are you getting

[sthomps]

I'm not getting any codes yet, but I was thinking of eliminating the EGR. Problem is in my area the truck needs to be emissions checked every two years. This is why I'm thinking of making a plug to replace the EGR, then replacing it when I get e-checked. I just want to figure out if I leave the good EGR pluged in will that keep the CEL off. Someone else had posted that the PCM needs to see a rise in intake air temp when the EGR opens or it will turn the CEL on. Is this true?

[sthomps]

Any ideas anyone? I just got my new truck (05) home so the work is going to start on the truck. It's locked up with coolant at the moment. I'm thinking the EGR cooler is split.

[Csolomon]

my truck threw codes but the light didnt come on... i have an edge programmer if that makes a differance

[fordfx4psd]

is it ok to leave the egr valve unplugged

[SCUFFY828]

Originally Posted by fordfx4psd

is it ok to leave the egr valve unplugged

if you want a check engine light yes its ok, does it fix any egr problems , no , if the valve is bad , it will still cause problems, i believe if it isnt broke dont fix it , if you unplug it allowing it not to operate , knowing how the system works its actualy worse to disable leaving all those hot gasses hung in the egr coooler , allowing it to operate normally at least allows it to open when needed and dumping the exhaust thru the engine like it was designed to do , unless comeplete egr delete is done , leave it as the factory designed it

[sthomps]

I found this paragraph on the fordtechservice site.

When normal EGR rates are being commanded and when the engine enters into either one of two specified
operating ranges, a flow check is performed. The operating ranges are defined to insure an adequate amount of
EGR is being requested to allow for an accurate estimate of the EGR flow percentage. At this point EGR flow is
estimated based on the difference between the Mass Air Flow (MAF) sensor reading and the total mass flow
calculated by the speed density calculation. The estimated EGR flow is then compared to the expected EGR flow
to determine if there is insufficient or excessive flow.

So if I'm reading it right. Unless your using a programmer, when the egr is deleted or flow is obstructed in any way the PCM is going to throw a CEL. Unless the MAF voltage is controlled somehow.

[davegr1]

Scuffy is correct, why mess with it if its working. But on the other hand, I welded mine shut and disconnected the EGR valve, 04 and older will not throw the CEL, they will give codes, but they are dummy codes. They will not affect the way it runs.