Alrighty! That's what I thought, but I'd thought I'd ask anyway. Thanks for the lead!

Dexmex has another thread going....you need the full story. Rarely have I seen a bad IAC cause Code 12. Vacuum leak is most likely cause. Then there is the known exhaust leak upstream of the O2 sensor.

I am merely replying to a thread to which I had replied much earlier and offered my input here; if he has another thread elsewhere then so be it, but I am leaving my posts as they are.

She*

Can I check the IAC? I was told once by a friend that you can unplug the IAC while the engine is running- if it stumbles the part is good. Never done it before though or know how accurate that would be.

Shoot I hate vacuum leaks. But I don't know the history of the truck, so it won't hurt at all to look for them.

Your friend is right , start it up and unplug it; does the engine RPM lower and/or die?

It stumbled and died right on cue. At least that eliminates a possibility. Like the gentleman above said- I have an exhaust leak, the exhaust manifold is toast. I'm not sure if that plays any role in the low idle/stalling. Moved to this thread because the one I created was EGR related, now solved. Thought I'd search for threads on this problem specifically!

Unfortunately it looks like I'll be hunting for vacuum leaks.... At least I'll get a few cigars out of it.

I was merely informing you DexMex has another thread going with more information of what is going on with their vehicle. Too many times someone jumps from thread to thread that makes it difficult for anyone to answer without knowing all the details.

No harm, no foul...glad that you replied.

2000 f 150
 

My 2000 f 150 has a new tranny. Replaced shift selenoids and wiring harness. The truck stalls when I put it in drive but if I two foot it and give it gas while letting off the brake it will sputter but won't die and it'll drive but as soon as I shift it out of drive and shift back into drive it stalls. Any thoughts on what this could be?

Welcome to FTE!

You might get a better response in the 1997 to 2003 F150 section of the site: 1997 - 2003 F150 - Ford Truck Enthusiasts Forums

1995 Bronco XLT stalls at lights and sometimes in reverse
 

My 1995 bronco XLT quits at lights sometimes and now its getting to where I have to keep ignition turned over till starts. Also, before this started it likes to stall when put in reverse sometimes. New plugs etc. Go uphill and A/C goes warm then back cold again too. Ibeen checked for vaccuum leak and nobody can see any. Help!

I've had the same issue with my Ford truck. I went through all the same things to try to get it from stopping. I replaced the throttle position sensor and it stopped doing that. The sensor goes bad and that's why you have to keep gas on it for it to smooth out. But my speedometer was bouncing around so I replace that also and them two run together.

Stalls when shifted to D of R solved
 

I had a 03 F250 doing the exact same thing. 5.4 Triton. Would die as soon as you put it in reverse or drive. Engine sounded good although I could hear a flutter coming from the exhaust. Customer told me that he had changed number 3 coil per a fault code. And it ran great for a short time. I noticed that the number two coil had been replaced and the number 3 had not. I pulled the number 3 coil and the boot was burned. Replaced number 3 coil truck runs great even when shifted to drive and reverse. Who would think a small Miss would cause the engine to die. Note, I can pull the hose off the brake booster which is a gigantic vacuum leak and the in the engine still does not die so a vacuum leak obviously will not cause this problem.

no it’s running rough in park now too

it idles a bit rough, which is a new thing also, but it will idle forever in park or neutral and not stall