1998 Dodge Ram 1500 4wd 5.9L - The truck starts up fine but when it idles for a little while it starts running rough and sounds like it's sucking air through the air filter loudly. It's not setting any codes. When accelerating (while driving) it back fires though the intake and it has no throttle like it's running out of gas. It does this for a couple minutes then it runs fine. It doesn't happen just once, it continually does this while driving. It does this when engine cold or hot. When idling it gradually start to loose RPM and eventually die (like it ran out of gas). Changed a few sensors and it didn't make a difference. Looked down throttle body and seen engine oil, what does that mean? Anyone have this problem? What was it? How do you fix?

 

Blown plenum, clogged cat, and fouled O2 sensors. Read the Plenum sticky at the top of this forum. (I am going to move it to the tech forum.)