F-1502000

I have a 2000 F150 w/a rebuilt 4.6L engine with approximately 87K miles. My truck has been showing the common EGR code for a few years, and most recently has been showing a cyl 4 misfire and a bad O2 sensor (at last check when pulling a trailer and the CEL kept flashing at high rpms/during acceleration when pulling a trailer). I updated all the plugs and #4 coil pack earlier this year. My truck has recently started idling rough and dying while in gear, but not while in park or neutral. It always idles fine at 600 rpm, and it started dropping from there down to 200 rpm, and wants to cut out and die.

Before I take it somewhere and spend a ton of money on diagnostics and repairs that don’t fix it, can anybody tell me if this is the O2 sensor or the EGR or possibly a timing issue? I can also hear a rattle when I start it, usually only after it’s sat for a while, like first thing in the morning or after work.

Jbrew

Can't really tell you anything without you posting the DTC's you have. That's what they are for, diagnostics. There's more than one code for each of the systems your having problems with. The DTC'e will help us help you. Sounds like you know them, I don't understand why you not posting them.

Also, I don't think your engine uses coil packs. Easy way to tell, if you have spark plug wires then yes you have coil packs. If not, your engine uses a COP system. However, in 2000 some of these models did have pacs. Very few though, most used the COP system....just coils, one per cylinder. These systems are trouble shooted differently, so you need to be clear upon which you have.

F-1502000

I couldn’t remember the codes. But I hooked it up and it shows a P0136 and P0401. And it must be a COP system, then. I didn’t replace any wires when I changed plugs or the coil, nor did I mess with any.

Bell Blue Raider

I'd start off with the egr valve and just for the hell of it I'd change the fuel filter and run a quality injector cleaner in the gas

Jbrew

I'd take it in if I were you, they don't idle fine at 600 rpm and won't even run at 200. Something very strange is going on, never heard of this problem in the past. Low battery maybe? Yea a low battery can cause the truck to go goofy, but that's all that comes to mind. Could have a plugged cat or air filter. For the rpms to be that low something is plugged or partially plugged.

F-1502000

The truck has always idled fine anywhere from 600-1000 rpm ever since I started driving it. Never below 500. It runs high when I first start it, then it settles to 600. And I can’t imagine a battery issue putting out an O2 code, could it? Or at least the battery light would have flipped on like when my alternator went out. And the CEL has, according to my mother, been on ever since they put in the rebuilt block and tranny. From what I’ve read on here and elsewhere, the P0401 code is an infamous code with these engines-the EGR gets clogged every so often and tells the computer something’s not right and flips the CEL on-to the point some recommend just doing an EGR delete and be done with it. The O2 levels were a flatline 0 when I plugged in the code reader today, too. As for the air filter, I replaced it here a few months ago when I changed the #’s 5-8 spark plugs. And I don’t have a clue what you mean by a plugged cat.

And Bell Blue Raider, the EGR valve is more expensive to replace than the O2 sensors. Or can it be cleaned like my dad blows air through the air filter every now and again to clean it out?

Jbrew

Like I said, it has some serious problems. Warm idle is exactly 725-730 rpms. 600 rpms is way out, none of these engines run at those rpms ever. It's definitely not in the programming. Ford calls it good between 700-750 rpms, but these trucks idle very predictably right in the middle of that.

A common problem is vac leaks, but with that the idle climbs to higher rpms.

Your talking rpms 600/500 these trucks just don't run at. So something is plugged up, it's the only reason for rpms that abnormally low. Go get those cats checked out.

Good Luck.

F-1502000

Hey, guys. I swapped out the circuit 1 bank 2 O2 sensor today, and that seems to have fixed the problem now. The idle is stronger and smoother. The only thing now is that it idles at around 700 rpm in park/neutral and close to 600 still in drive/reverse, foot on the brake. I also got some in-fuel injector cleaner and plan on changing the EGR valve out soon to cover more bases. Thanks for the advice.