Timing problem with a VX

[GasSavers_Ryland]

it sounds like the clutch is starting to grab properly, as the RPM's drop, they it starts to slip again, if it just feels like the engine speed is droping, and the tac reads the same then it's the o2 sensor, if someone checked it out and said that it is a problem with the timing, then I would guess that the timing belt is off by one notch, as the timing belt should line up with a 2nd arrow, insted of the top of the head like most cars, and is commenly installed wrong when replaced, but I would start out with a test drive, and offer at least $500 less then the asking price because of the "cost of fixing the problem"