The OVP is apparently programmed to self destruct after ownership changes. I can't count the times I've heard "Previous owner said he had NEVER had any problems with the car, but two weeks after I bought it the 'check engine' light came on and it began to [ hard start cold, hard start hot, stall, ABS light on, skip, roll over and play dead, etc, etc, etc. ] Go figure! Of course replacing the OVP doesn't actually fix any of the problems but it certainly sells a lot of OVP's.