Volkswagen :: 2005 Golf Loses Power / Runs Bad In The Heat

I have a 2005 VW Golf GL, automatic tranny, 2.0L 4-cyl that has some issues during long drives in hot weather. The 1st incident occurred when I was driving on the interstate in AZ w/the outside air temp around 100 degrees. It was a flat, desolate stretch of road and I had cruise control engaged as well as the A/C turned on. Suddenly it was as if someone had let off the gas pedal, as the car began quickly slowing down from 70 or 75 to maybe 40 or so. I turned off the cruise control & tried to increase back up to highway speed manually, but there was a long lag time before the engine kicked up again. I got it back up to full speed, then moments later it would kick down again unexpectedly as if I had taken my foot off the gas even though I hadn't (and I was still not climbing any hills). The temp gauge was still normal, but I turned off the A/C just in case this was making an unnecessary drain on the engine. Still the car would behave in the same way. I took the next exit, let it rest a bit, then limped along @ a slow speed on the frontage road until the next town. Suspecting it was the MAF sensor, I had it cleaned @ a repair shop before heading back home. It ran normal for a little while during the drive back, but then the same issue.

Back in town, I replaced the whole MAF sensor, since I was told just cleaning it was a temp fix. By this time the outside air temp was cooler, & short drives to/from work went fine. However, the next time I tried taking the car on a long hot drive (from SoCal into NV), the same issue happened again! So maybe it wasn't the MAF sensor afterall (unless the replacement was faulty?). Nevertheless, I took a wet washcloth & wrapped it around the sensor, & this seemed to do the trick to get me back home again. For now I am no longer going to risk taking this car on long hot trips until I can figure out what's wrong w/it & how to fix it. I do plan to take it to a mechanic but wanted to see first if this rings any bells for people on this forum.....??

2nd, (possibly related?) problem:

Today as I was coming home, the engine stalled when I tried to take off when the light turned green @ an intersection. I limped it to the other side, pulled over, & tried starting it up again. It started right away & then ran fine. I'd been low on gas but not so low that it should be an issue. I drove the rest of the way (on a highway) to a gas station (several miles) w/o A/C, no problem. I filled it up, did the washcloth trick once again in case that was related to the problem @ all, & drove the rest of the way home just fine. Battery is relatively new (about 2 yrs.) & alternator tested fine. Did not see any corrosion on a recent check of the battery posts. Outside air temp warm today, but not that bad...only mid-80s. Temp gauge read normal.