Lambda sensors advice please!!!

[MagicDoormouse]

I'm fitting a performance manifold on my VTR but CANNOT get the old sensors out of the old front pipe and manifold. I have managed to get the pre cat sensor locally (a universal one) but not the post cat one. My question is, would I be wise to get another (universal) pre cat sensor and use that post cat? Hope I've made sense?

[Bedford126]

Just use heat to get the old one out?