I have seen post similar to this but no fix! This weekend after replacing a bad battery on my 04' f150 screw 4.6L, I noticed a check engine light come on, the code is P0506 and my truck runs a little rough at idle,not bad though. Any ideas on a fix for this or what may be causing it, I have heard IAC, throttle body or throttle body is dirty but haven't heard any fixes, any help I would appreciate, thanks!!!

 

Clear the code, and drive it. For whatever reason, some '04+ F150s go into fail safe mode and/or set random codes when the battery is disconnected and reconnected. Clear the code and try again.

 

I will try this, I wouldn't think it was anything since the vehicle was doing fine before I replaced the battery! Thanks for your info!

 

I just read your post, and I had the same problem. Just replaced the battery on my 2004 F-150, and the next day the service engine light came on. After a week of driving it, the idle seemed to be acting wierd, and it even died at a stop sign. I took it to the dealer today, and even though its still under warranty, they said this problem was not covered. They said it was the throttle body that needed to be replaced. Before giving them the ok on replacing it for $430, I decided to check on here, to see if anyone else had the same problem. I just told them to leave it, after I saw you had the exact same problem, after changing your batt. I will try clearing the code aswell, hope it works.

 

Yea I hope it does to, I found a throttlebody price online and I think it was $110.00 with do it yourself labor but....I dont want to buy a throttle body and not be for sure that that will fix it, so...I will clean my throttle body and reset the code and post back here tommorow on how it goes, thanks for the advice guys, hopefully I can share some input!

One more thing: When my truck was newer around 28K, I had the problem with rough idle and they replace my throttle body back then and it fixed it but surely it can't be bad again, that would be ridiculous! I remember askin them and they said the rough idle prob on the 4.6 was the throttle body and on the FX4, they had to replace the PCM, but I remember well as my truck would die at stop signs or go dead as I was making a slow turn! Weird!

 

Well...we'll see what happens but yesterday and i took and cleaned my throttlebody and it was pretty nasty with gunk, cleared my code and so far after about only 45 miles, my truck has been driving great and idling fine, so hopefully that fixed the problem! If I were you guys I would definately consider cleaning your throttelbody casue with all the crap thats probably in our gasoline these days, thats prolly alot of the cause on the buildup! I'll keep you guys posted!

 

Hey Motox,
Im cleaning my throttle body as we speak, and was wondering if you bought a new gasket, or just used the old one?
Also, did you just clean the throttle body, or did you clean the piece that connects to aswell(peice connectong the throttle body to top of manifold)?
And lastly, how do you clear the code? Is there another way other than disconnecting the batt?