Gen 5 O2 sensor on 3.0R-B problem?

[Langer_95]

So I just looked at a 2005 3.0r-b and the guy lost the original o2 sensor so he got a new one but it was for a Gen 5, would this be a problem later on and shouldn't purchase the car? Thanks

P.S the car is on the forums. viewtopic.php?f=3&t=27212

[(sic)]

Not sure compatibility wise but a new genuine front o2 sensor is ~$200 delivered to aus. Recently replaced one myself.