Sounds like it was corrupted somehow, what year is your Marauder? There were 3 factory tunes as far as I can remember, all 04's had the MAV2 stock tune to accommodate the Traction Control switch that was added and maybe some minor tweaks. Can they upload and download from your ECU?
There is no lock, have them check the vin in the ECU and see if it's corrupted. I have the MAV2 stored on my laptop for the sniper programming system if you have an 04 and want it. I am sure others here may have it in SCT format too..
Your best bet is to bring it straight to Ford and have them hammer it on their proprietary system back to stock with your original vin. Then take it from there with a reputable tuner who can hook you up with an new tune and an SCT so you have everything in your hand set for your car. This whole venture won't be cheap though.
You can also see if anyone here has an ECU which is stock with a stock Ford tune which matches the sticker inside your door jamb. A tuner with a full blown SCT system may be able to vin match it for you I think, the dealer definitely can. This way when you go for an inspection, it will all jive on the emissions sheet.
Just so you know, a "No Communication" from the emissions shop may be several things, If they can get in and read the ECU, then there is no problem beyond that the stock tune is not in the ECU. The "No comm" is from each emissions item their computer is polling but is turned off in the aftermarket tune like your rear O2's. This will spit out a 12 foot long defect sheet from the emissions shop because generally an aftermarket tune will turn a lot of stuff off that it no longer needs to see. This will wreak havoc with the emissions shop computer because it will get a "No Comm" code from the O2's etc.. That will generate a fail on their end and label everything "No comm" If your emissions sheet shows some stuff working and other stuff messed up, there is nothing wrong with your ECU, but you will need to upload the stock Ford tune for our cars to pass. That you will need to get, then get someone to read and save your original tune and then upload the stocker, read and save that. Wait a few days after uploading the stocker so it doesn't have the "not ready" flag in the ECU, get it inspected, then roll it back to your non stock tune in the lot.
You need to get the stock tune with your vin stored on a tuning device along with what is in there. You usually cannot upload a stock tune with any aftermarket tuning boxes with one vin number when the ecu has another because the aftermarket stuff uses the vin as a guide so you can't upload tunes to your buddies car since his vin is different...
