So a few weeks back my 98 F150 4.6L threw the excessive flow code (can't remember the exact number). It has 120K. So after an hour or so of searching this forum I found out that it is typically caused by a bad DPFE sensor. So I went ahead and replaced both the EGR and DPFE sensor. My symptoms are better but asymptomatic. Now the thing either runs fine or it won't start unless I give it gas. I say it starts right up and dies instantly about 60% of the time. I have to feather the gas while working the auto tranny to keep the idle up....if not it stalls. I typically do this "dual foot routine" for a few minutes. Basically, I'm power braking the thing to maintain idle while coming from or to a stop. After a few minutes the truck idles just fine by itself. No codes.

Any thoughts?

 

Do some searching on the forum. Sounds like the IAC idle air control valve.

 

I've been searching. Thanks for the input will check it out.

Could this be a clogged throttle body? Reading that can also throw the P4101 code. Thing is, my truck isn't throwing any codes.

 

you probably did this but check to see that all your vaccum lines are still hooked up, might have accidentally disconnected one. another way to tell is iff you hear a high sucking sound that second or two it's running. I would still verify all lines are still hooked up or even better one of them broke or has a hole in itand needs to be replaced. I know because when i was checking something once I acidenatlly disconnected and acted the same way. I knew because I heard the sucking sound. Hope fully it is that easy. If not then I agree woth 92merc it is probably the IAC valve.

Lance

 

An IAC valve can go bad and cause the issues you have been experiencing without throwing any codes. Been there.

 

No codes thrown. I will check the lines but when I replaced the DPFE I didn't notice anything wrong with them. Thanks. I'll be getting a IAC shortly.