1.2TSI, 11 plate, 106k miles.

Local garage replaced throttle housing, using non-OEM parts to save money. Since then the idle revs are low (just over 600rpm) and once the engine's up to temperature, the traction control light comes on after a few seconds of idling (ie the first time we stop at lights or a junction). Turn off ignition and back on again and all is fine till next time.

The diagnostic computer is showing a problem with the air intake, but nothing more specific. Garage suggests it might be because the non-OEM throttle housing just isn't communicating perfectly with whatever it needs to communicate with (bear with me, I have no technical knowledge!), and that it'll be something to live with. He's reluctant to send it back for a replacement as he'll have to stump up the bill if it's tested and found to be fine.

Where do I go from here? Would a Skoda/VW garage have more-specific diagnostic equipment to better isolate the problem? I'm not jumping at that immediately as not wanting to throw too much good money after bad on a car that is ageing. But if it's what's needed, then so be it. Any other ideas, either on the problem or getting better diagnostics?

Thank you!

Sounds as though this garage may be a little out of their depth.

Assuming this is a CBZB engine code version of 1.2 TSI, there is no 'communication' as such from or to the throttle body.

It simply has two wires going to its dc motor and a further 4 that serve to provide analogue positional feedback to the engine ECU.

When such a throttle body is replaced, it tends to be necessary to perform a throttle body alignment/adaptation (TBA). A device is plugged into the car, which puts the engine ECU into a mode where it learns the voltages of the feedback potentiometers at each end of the full range of movement of the throttle valve.

Ask your garage if they performed this alignment after fitting the replacement.

Thanks for this. I just checked in with the garage and they said they tried but couldn't do the alignment because of something not communicating with something else. I'm sorry I don't have the technical knowledge to even relay what the somethings are in that sentence (!) but it sounds as though they know what needs to be done, it just wasn't possible to do it. Beyond trying again, or getting a replacement throttle whether that be OEM or otherwise, they're at a loss to know what to do. Any other ideas? The engine is CBZB btw.