i gotta replace the o2 sensors in my truck cause i failed emissions.. thinking its cause the headers so i bought some new ones and couldnt get the connectors apart on the truck.. is there a trick to doing it or am i just not trying hard enough, i pulled the little red tab back and pulled pretty hard but still couldnt get them apart.. does anybody know wats up?

 

There is another tab that you have to push on to unlock the connector. It is kind of like the fuel injector connectors where the little red piece just locks the main tab that actually holds the connectors together.