Bucking 4 door bronco

[MarauderMedic]

I have an '04 MM, it has a K&N CAI, Magnaflow Mufflers, and a Diablo Sport tune. I have had an issue lately with the alternator. The factory one failed back in July last year and replaced it with a Pep Boys alternator. Just last month, my battery light came on and it was overcharging. I figured it was an issue with the alternator again so figuring it was under warranty, I got a replacement. That one lasted 5 days before the battery light came on and now it was under charging. I replaced the battery and it seemed fine, until 4 hours later the light came back on and it showed low voltage again. The next day I took it to my mechanic and he said the alternator was the issue. I had to bite the bullet and replaced it with a Motorcraft alternator and hasn't had a problem with voltage since. Now, I'm starting to have an issue with the car bucking under slight acceleration. Doesn't matter what speed, or what RPM. Went to Atlantic City for the night last week (thats when the problem started) and my airbag light started flashing then it became steady on. I took it to my mechanic and checked to see if it was an ignition problem, so he checked the coils, and plugs, and saw that they looked fine, plugged it in and showed them firing just fine. When I drive it, I have no vibration except for the shudder I feel. I can hear the exhaust "puttering" when the problem occurs. Along with the "puttering", I hear a relay or something shutting off then turning on under the dash. I cant figure it out for the life of me. Please help!!:mad2:

[Ozark Marauder]

It was COPS on my car.....some other possibilities here:

http://www.mercurymarauder.net/forums/showthread.php?t=72162

[MarauderMedic]

Yeah I had already read the thread. That's why I had my mechanic check on that. Went through everything along the lines of ignition and plugs. Came up with nothing. Funny thing is I was doing the same thing you were doing before I even read your post with the OD.

[Ozark Marauder]

I have an '04 MM, it has a K&N CAI, Magnaflow Mufflers, and a Diablo Sport tune. I have had an issue lately with the alternator. The factory one failed back in July last year and replaced it with a Pep Boys alternator. Just last month, my battery light came on and it was overcharging. I figured it was an issue with the alternator again so figuring it was under warranty, I got a replacement. That one lasted 5 days before the battery light came on and now it was under charging. I replaced the battery and it seemed fine, until 4 hours later the light came back on and it showed low voltage again. The next day I took it to my mechanic and he said the alternator was the issue. I had to bite the bullet and replaced it with a Motorcraft alternator and hasn't had a problem with voltage since. Now, I'm starting to have an issue with the car bucking under slight acceleration. Doesn't matter what speed, or what RPM. Went to Atlantic City for the night last week (thats when the problem started) and my airbag light started flashing then it became steady on. I took it to my mechanic and checked to see if it was an ignition problem, so he checked the coils, and plugs, and saw that they looked fine, plugged it in and showed them firing just fine. When I drive it, I have no vibration except for the shudder I feel. I can hear the exhaust "puttering" when the problem occurs. Along with the "puttering", I hear a relay or something shutting off then turning on under the dash. I cant figure it out for the life of me. Please help!!:mad2:

What was the flash sequence of the air bag light?

http://www.fordwiki.co.uk/index.php?title=Airbag_Flash_C odes#Symptom_Chart

"Possibly the EGR, a problem with the EGR can create some really severe bucking is because the tune adjusts for the amount of recirculation that it is commanding. If that recirculation isnt there then both the fuel mix and timing go WAY off. So far off that they are out of range for adaptive learning to correct and that is what does it.

With the proper EGR flow the engine can run a lot more timing because the recirculated gasses actually cool combustion. Add that timing in to a hot and incorrect mix and you are going to get some ugly problems."--Darrin

Other than these Bro, I'm at a loss :confused:

OZ