Have a mk7 2012 fiesta edge on lease from ford dealership and wondering if I can do anything to it 'under the bonet' and return to stock for service/hand back?

You're best off reading the terms of your agreement very carefully.

You don't want to infringe a condition which results in ulfm cancelling the agreement and taking your car back.

If you're thinking of remapping be aware that there is a rumour that doing so leaves a hex code on the ECU that Ford can find.

As long as it's returned to standard and had no adverse effect I don't think they'd have a problem with it.

Obviously make sure the insurance company is informed.

Cheers!

First mod really just thinking of upgrading air intake, then maybe exhaust and just replacing before my service and return

It doesn't void my warranty if fit air filters etc, so does that mean it doesn't void my lease?

Actually if ford warranty still works the same if you mod the engine even slightly you void the engine warranty not the whole car

Tread very carefully. Even filter upgrades, if not Genuine Ford parts, could render the warranty on the engine void if they know about it.

They will likely tell you, if asked, that they would not approve any modification. They may tell you that your mod will devalue the vehicle at the end of term. If you offer to have it put back to original spec they will throw the, what if you do not honour the terms of lease and the car is taken back early scenario at you.

Lease companies are open to suggested modifications prior to agreement whereby they can take the mods into consideration and factor this into the monthly payments.

Best advice id say is do not ask them