Hi Dominic,

"Inlet air circuit" is a common DTC on Reaults, it is unlikely to be anything to do with Inlet Air Temp sensor! More likely to do with inlet air leak or poor manifold vacuum.

It sounds to me like you may have a throttle body problem with this one. Check manifold Vac and remove manifold and TB thoroughly clean and refit then "reset autoadptives"

If this does not work it may need a new throttle body. The last time I priced one they were ~£350.00 from Renault and no one else at that time supplied them aftermarket.

Also check wiring where security plate rubs on ECU harness close to multiplug. And confirm MAP sensor is reading correctly.

HTH

Mike