Is remapping nessecary if installing uel header?

[Is remapping nessecary if installing uel header?]

I thought so too. Just curious if anyone had run one for a while without a tune.

[Is remapping nessecary if installing uel header?]

Been looking into going with unequal length headers but was unsure if a remap is absolutely necessary straight away. Will the cars ECU get confused? Can you run the car reliably for a while with uel's on the stock map? I understand that a map will give gains and help with overall performance and I do intend to map it eventually. Just a big lump of money to do the two at once. Any help is appreciated.

[Agency Power UEL Manifold - De-cat - SOLD]

Is this still available and where is the collection from please?