2011 Focus 1.8 Duratec - Mk2.5 Focus acceleration/throttle issues? - LeDonkeh

Recently bought a 2011 Focus. It had an issue where it would nearly stall at idle, this brought up a P2135 code and the dealer replaced the throttle pedal which fixed the issue.

However, over long distance journeys-150 to 200+miles it has a habit where it begins to feel like the car is braking gently, only slightly perceptable and almost like hitting a wall of air. Aftef 10-20 minutes of this the "i" light comes on displaying engine malfunction and then goes into reduced speed mode. Restarting the car fixes the problem and thus far I have been unable to diagnose the issue. Additionally as low speeds in first/second it surges slightly, only 10-30rpm, is this another issue or normal?

The oil is fine, so is the coolant. Ive checked the air filter and tube they're both clean, as is the face of the throttle that I can see. Ive pulled the spark plugs and theyre all good as well although I dont know what the gap is.

Any ideas? Much appreciated

2011 Focus 1.8 Duratec - Mk2.5 Focus acceleration/throttle issues? - elekie&a/c doctor

If the Mil light has come on ,then I would think that some fault has been detected and stored. Has the diagnostic system been checked since the pedal replacement?

2011 Focus 1.8 Duratec - Mk2.5 Focus acceleration/throttle issues? - LeDonkeh

The engine light hasnt come on, just the information light, and intermittenly so. Diagnostics were run after pedal was installed, checked for updates and issues etc with no luck. Back into the shop ob friday to see if they can find the fault.