Check Engine Light On problems of the 2004 Volvo S80

My wife was driving our two kids in our 2004 Volvo S80 on I-75 when the vehicle just completely stopped operating. She could not get the vehicle to the side of the interstate as when she pressed the gas pedal, the engine would not even rev up. My wife an children were stuck in the middle of the interstate in a car that wouldn't drive. The dash stated "reduced engine performance". She called me on my cell in a panic as cars on I-75 were flying by her and swerving out of her lane to avoid colliding with our vehicle. I asked her if she had tried turning off the vehicle and restarting it. The first time she tried, it did absolutely nothing. The second time, it started up without the "reduced engine performance" on the dash but it stated "check engine" on dash. My wife was able to drive the vehicle off and get it home. I took the vehicle to the Volvo dealership in our city and informed them what had happened and that I had done my research and thought that it was probably the electronic throttle module (etm) and that it might be under a 10 yr/200,000 mile warranty. The Volvo dealership informed me that there would be a diagnostic fee to start. When I got the car back, the dealership informed me that I had carbon build up on the throttle pad and that after cleaning this, the etm passed all of the tests. The next day, the check engine light came back on and the car started to leak gas out the back in huge amounts after I stopped to get some gas. I took the car back to dealership and they looked at it and after fixing it, informed me that they had kinked an o-ring while performing a recall on something on the gas tank and this caused the check engine light. Upon driving home, the check engine light came back on again. Upon taking back to dealership, the dealership admitted that they had not done a diagnostic fee the first time so that had no idea if the etm was fine or not. But this time the diagnostic showed the etm needed replacing. But no warranty on 04.