There r 2 kinds of swapped feeders or sectors u may detect when making a drive test.
1- cross sectors, feeders (TX, RX) of sector 1 are used for sector 2 and Vice versa.
U detect this when u r in the coverage area of S1 but u find you are served by the frequencies of sector 2 and when u need to make a HO to the other sector, it occurrs in an opposite way.
2- cross feeders, feeders(TX,RX) are connected in the place of each other in a certain antenna.
There will be no coverage transmitted by this sector.
When u make a DT. U will find that sector is not serving.
U may suspect the sector us down or crossed sectors.