Well, my 2004 V8 sport is back at the dealer for the fifth time in five months, here's a quick recap:

1) Pulling out into traffic, engine stalls. Starts right back up, will idle (very rough) but car won't go more than about 3mph. Codes for throttle position sensor, dealer replaces TPS and throttle body.

2) Less than a week later, cruising along at 40 mph engine stalls. Will restart and rough idle, but car will not even move. No DTCs, dealer unplugs MAF and the car restarts and runs. Replaced MAF.

3) Three weeks later, cruising at 70mph, engine stalls. Will restart and rough idle, but car will not even move. No DTCs. Dealer unplugs MAF, car runs. I mention the problems I have read on this board about #4 coil causing computer interference, they assure me that this is not my problem and will not replace it. Dealer replaced PCM, and drove the car for a week.

4) Another three weeks, cruising along at 55mph, engine loses power but doesn't stall. Will chug along at about 5mph, but if you floor it it takes off at full power. Codes for one bank too rich, one bank too lean. Dealer clears codes and can not duplicate problem. Still not willing to try replacing #4 coil, but agree to swap it to the other side. They drive the car for 2 weeks with a data recorder, then give me the car to drive with the data recorder. Transmission is acting funny, wants to hold gears too long. Also feels like a neutral drop between 2nd and 3rd gear, tach will wind up 1000 rpms then thunks into gear. Transmission will not act up at the dealer of course. After about a month without engine problems the dealer pulls the data recorder, tells me when the transmission is acting up on a regular basis to bring it back.

5) Two months later. Sitting at a traffic light, starts to idle rough. Light turns green, everyone else goes. I chug along with a maximum speed of about 20 mph. I'm less than 2 blocks from the dealer, so I pull it in. Codes for both banks lean and O2 sensor stuck low.

Anyone have any ideas what is going on with this car, the dealer doesn't seem to have a clue. They called it into Ford's tech people, they're the ones who told them to replace the PCM and put the data recorder in, they are clueless as well.

If they won't replace the coil, have them move it to another cylinder and see if the problem goes away. Or you could do it yourself...

I think they already did that. #4 ;)

My bad. Not enough coffee yet.

lol me either.

with banks lean sounds like you could have a major vacuum leak somewhere. this could cause the stalling, the misfiring, etc. failing tranny can certainly cause stall at idle if t/c is acting up but I've never known one to stall an engine on the freeway.
BTW the interference could be a coil other than #4, #4 seem to have most issues due to proximity to the pcm but others could cause this behavior as well....i.e #2, #3, etc.

You did not mention - during all of these issues are you getting the ETC failsafe mode message on the message center?

Nope, never had the ETC failsafe mode message. A few times when driving I have heard the computer warning tone that tells you to look at the display, but there is no message.

the ding is the mysterious check transmission msg that clears before you can see it.

Yeah, that ding bugs me. I automatically think I hit the traction control so my first reaction is to look at that button.

I have said all this in numerous other threads but i guess i can give you the latest. Eight months ago i got throttle body codes and stalling/failsafe mode, they replaced the throttle body and three coils, car ran fine afterward. Two months ago it develops a misifire, dealer replaced two plugs and coils. Car ran fine for alittle. Last week i took my car into the dealer again, which by the way i am at 52970 miles currently, past the warranty. It had developed another problem with throttle codes and failsafe mode. In my case i had to drive around with my code scanner, when it happened i had to pull off, shut down, scan and clear codes, start up and get about 1-2 miles before it happened again. So when i got to the dealer i was nice but pretty persitant about things. I immediately bypassed the little service fairies that swarm you when you pull up and asked for the service manager. So i now get the guy wearing a nice suit and tie, explain all the previous problems, show him all the old paperwork showing said problems and he tells me that they'll take care of it, they give me a free rental(Ford 500) and send me on my way. Service advisor calls that afternoon, says they replaced all three of the remaining original coils and its ready to go. Invoice was $309, my charge $0. They told me they billed back FoMoCo for three previously replaced coils which covered the cost since the car was technically out of warranty. So they hooked me up good and the car runs fantastic. The car is way more enjoyable went its running great.

Anyway, the cause for all this B.S. per the service Manager....the coils. It all falls back on the coils. All the throttle bodies and MAF they replace arent necessaery but are what Ford recommends. But the root cause for most if not all issues are the coils. He said the newer F150 supposedly had the same kind of problems, and that its a common "Ford" problem.

It's a #%*(ing Ford, that's its problem.

Sorry, do I sound bitter just because my POS Lincoln is sitting in the driveway with me unable to complete the "simple" repairs of the upper control arm replacement on one side, and the hub/bearing on the other. Don't worry, the hub and bearing isn't a press fit, so it will come right out... riiiiight...

One thing I noticed wheni checked the coils on my car last weekend was that several of them have developed hair-line cracks in the top of the coil. This allows moisture to get into the coil and will eventually short it out. A simple fix is to spray the top of the COP with a heavy layer of silicone lubricant. OR coat it with di-electric grease. That will keep the moisture out, which in turn prevents issues like this down the road.

Of those people who have had the coil problems, have you always received coil misfire codes?

Nope. I only got a code when the coils went completely dead.

Well, they finally replaced one of the coils - #2. Also an O2 sensor. Guess we'll see.

The only odd part about your ordeal is I think those of us that have been through this with 03+ have all gotten the etc failsafe mode.

Also, we didn't report lean conditions or stalling on the highway.

I'm now leaning toward fuel delivery. Pump failing, bad regulator, etc...but we will see! Best of luck.

Not only did it not go into ETC failsafe, two of the times the engine was running so bad it would barely idle, and it doesn't give a single DTC? You would think it would at least know something's wrong.

Well at idle, a vacuum leak or bad maf could certainly cause enough of a bad mixture to kill the engine. The stalling on the freeway is very odd and in my opinion would rule out a vacuum leak, etc. There are much better mechanics on this board than me, I'm curious what their thoughts are.

One more question. When the tech pulled the maf and ran the car did it go into etc failsafe mode then? With maf pulled it ABSOLUTELY should go into etc failsafe mode.

Don't know for sure if it went to failsafe when they plugged the MAF but would assume so.

Didn't even make it a day this time, it's back at the dealer with O2 sensor codes again. Sounds like it has an intermittent vacuum leak.

Tell them to smoke test the evap emmissions system, and the intake vacuum system.

Intake manifold gaskets is the diagnosis of the day. Seems strange with only 24k miles, also doesn't seem like that would be an intermittent problem.

I cant believe they still arent going the coil route. Its got to be the easiest and cheapest thing for them to fix. Your stalling and only going 3 mph is exactly what the failsafe mode does, although you said it isnt giving the warning message. Coils seem to be the root of most problems and the car is very sensitive to them. Before this last visit i had a misfire which was only apparent here and there but no codes. I decided to put two new coils in and it started giving me throttle codes and failsafe again. How is it that two new coils cause it to run worse and start throwing throttle codes? I dont know and honestly i have given up on trying to understand it. All i know is the dealer replaced all the remaining original coils and it runs perfectly now.

im having the same issues now and i did get the check engine light on for about 2 days and then it went away but when i merge into the higway and push the car hard the check engine light keeps blinking and that is a missfire according to the manual, im taking the car in on monday.

I was driving the other night and this guy in a lincoln towncar was tryin to race me for some reason. I just threw her in 4th and floored it and just left him then all of a sudden the check engine light goes on my car looses a whole bunch of power and she starts to buck a little bit and stutter. Then that guy just flies right by me. I was pissed cuz at the time i didn't have any clue as to what happened and it certainly wasn't worth playing around with that guy. So at the light i threw her in park and turned it off. Started the car back up and the light went away and to my dismay it started stalling again. I went to autozone and it read cylinder 6 had misfired. The next day i went got a coil for 45 bucks and just went and installed it myself. I just want to say don't let a coil intimidate you it is a fairly easy job to do. It'll save you so much more money, plus i'd rather work on my own car. Because you can't trust too many ppl these days. Its all about money they'll try to get you to buy stuff you really don't need. If you do it yourself you'll know what youll need or not. There is a lot of help on this forum and write ups. I never done this before on the LS, all you really need is a 7mm wrench and some sockets. Oh and a lot of patience....It took me about two hours because i kept dropping the wrench and loosing it in the engine bay. But now my car is all fixed and she's at full power again. I guess my point is, if you have the time just simply do it yourself. Why get F*&k'd at the dealer i think it's their job to try to sell you as much stuff and suggest this and that. When it's something as simple as a coil definately do it yourself. It'll save you a lot of cash, and the way gas prices are i can use all the cash i can get...

Thats funny you mentioned a town car racing. Yesterday morning this 75 yr old guy with old captian hats in the back window was just tearing thru traffic in his towncar. I mean he was driving like a 16 yr old in a honda. Totally crazy.

I just want to say don't let a coil intimidate you it is a fairly easy job to do. It'll save you so much more money, plus i'd rather work on my own car. Because you can't trust too many ppl these days. Its all about money they'll try to get you to buy stuff you really don't need.

Replacing the coils isn't at all intimidating, it's just that the car is still under warranty.

Intake gaskets make sense. Sounds like MAJOR vacuum leak since showing lean codes and highway stalling.