I did the MAF and silencer elbow mod the other day and while I had it all apart iI figured it was a good time to see if the throttle body opened completely when the pedal was pressed all the way down. Not being able to do both at the same time I enlisted the help of my daughter who was all too happy to mash the gas pedal to the floor.

I was glad to see that it did open up all the way but when I saw the back side of the butterfly it was nasty dirty. I could'nt understand why at first because the MAF and the elbow were very clean but I saw that the EGR valve was bolted on alongside the throttle body and immediately knew why.

Is the EGR crapped out? The engine runs great, no miss or rough idle but I can't believe it should be that dirty after only 19,000 miles. I wiped off the rear face of the butterfly with a clean shop napkin but there's more dirt that I can't reach.

Do you think something is wrong or is this common?
Is there a way to clean it up?

TIA, anxiously awaiting your advice.

 

Don't loose sleep over it; it's pretty natural. If you read the little note on the top of the throttle body, it says to avoid cleaning the throttle body, as it may contaminate the engine itself. While this may seem contrary to what seems right, it's normal!

-Flea