i got the worst tune up from purrfect auto on E. Charleston in Las Vegas (Aviod!!!). The weord thing besides the bogg is the heavy sucking or hissing noise as I accelerate. This is the wierdest of all/
Yup air filter. The reason I asked is because I had that same problem that you had and it was because the centerpiece of my cone air filter broke off of the air filter and made it's way down the intake and stuffed my intake hence my car couldn't breathe.
Since this is something so stupid and yet so unnoticed, I figured I'd throw that out there just in case. Honestly, it seems that when this happens to these cars it can be a number of things ie. the TPS, the AFM, a burnt out sparkplug, a burnt out sparkplug wire, bad rotor, bad distributor cap, fuel pump, etc. etc. etc.
Also, unfortunately for you, not only was that shop in Vegas a P.O.S., just about all shops in Vegas are P.O.S., so goooooood luck!!!!!