One of the aforementioned quick-change joints pulled that on my wife a few years back. The car she was driving at the time was starting to have some acceleration problems. I told her it was most likely a clogged fuel filter. She thought it just needed an oil change, which it did but that wasn't the problem. So she asked them to look at it when she took the van down for me for the oil change. They convinced her it was the transmission fluid, and charged her an extra $70 to flush and replace it.
Lo & behold, no change in peformance. So they wanted to do more repair work. That's when I got involved.
And sure enough, the problem was... a clogged fuel filter.
Fast forward to last December, her Olds (now my Olds) starts doing the same thing, about the time for the oil change. She panics. She's ready to sign off on gahd knows what (from the other place). I take it for a test drive... and go straight to our mechanic. Want to take a guess as to what it was?