New induction system and limp mode

[Focus bwoy]

I have a 2015 focus st tdci and recently brought a new induction system for it but it keeps putting the car into limp mode, I believe it is because of the maf sensor. I just wondered if there is a way to stop it going into limp mode with the induction system on without making car run like rubbish. 

[ThaiFiesta]

You don’t provide enough information to assist. Is the induction system designed for your engine? Is the MAF adapator the same diameter as the OEM one? Is the MAF sensor installed correctly (they are one way)?

[Focus bwoy]

It's a k&n 57s-4000 that's is designed to fit it and it's the standard maf sensor 

[ThaiFiesta]

If it’s installed in accordance with the instructions (https://www.knfilters.com/instructions/57S-4000_inst.pdf) then I’d say it’s either a leak or the sensor is dirty or damaged.  

[I'mAnExpertTrustMe]

You'll want to have a look into the error code causing limp mode. I had the same issue because the previous muppet owner put on a cheap cone filter, meaning that too much air was being sucked in.