Alright, so far, Have new plugs, new Plug wires (OEM ones now after the NAPA brand failed), New Coil Packs, and a New alternator. Engine is running smooth, very smooth.. In Park. When on the road, spits, and sputters when you give it too much throttle, then the M&S lights start flashing.. again. You can then pull over, turn off the key, start it again, and the problem clears until you give too much jojo... I dunno.. Any ideas? Oh, and Battery has a full charge.. If you sat in it in a parking lot with it running, you'd never know there were problems, your can rev the engine to your hearts content, the second you hit the road, all bets are off, 80% of the time, you get the M&S lights flashing.

2003 Land Rover HSE..

 

Hmm....mine did that some time ago, and it turned out to be the MAF, however, my M&S lights were not flashing. When the M&S lights are flashing it means that the tranny isn't getting enough power. Where did you get the alternator from and is it new or remanufactured?

 

Sounds like the MAF is going bad... replace and retry.

 

Sounds to me like either bad battery voltage or a bad XYZ switch.
When you say it spits and spudders is it actually the engine or does just the whole truck buck and yaw?

 

Don't replace anything until you can pin point it, that just puts you in credit card dept. Some of these truck parts are not cheap.

 

I bought the Alternator at Autozone I'm assuming it's remanufactured, I suspect most of them are nowadays. It is an exact match for the one I replaced though, even the same brand name on the side Valmont or something like that..

 

The whole vehicle bucks and yaws, but feeling the pedal, there seems to be a "Happy place" during acceleration, where it's running smooth, butt too much accelerator and you get the buck and Yaw, and the M and S lights flashing, too little is the same thing..

 

I bought a remanufactured alternator from autozone for one of my other cars and it didn't even last a year. I'd go to autozone and have that tested as well as your battery. How do your battery terminals look?

 

That sounds like a MAF issue or a air intake leak to me.
However if the battery voltage is to low the transmission computer will act up.

 

SO, I haven't been on here for a while.. I wanted to say thanks to all who had constructive ideas and such it was a big help. The vehicle is running like a champ now. It turned out that the flashing M+S lights and "Limp" mode were due to a bad air bladder on the passenger rear... Apparently whenever I was banking, or taking a sharp turn, the height sensor would get "tripped" for lack of a better word, apparently part of the safety suspension system? Or something like that. Anyhow I replaced both of them on the rear in September 2011, and haven't had a single glitch since.. Hopefully this will come in handy should anyone have similar problems to mine.