Mates got a 1.2 2006 fabia thats turned into a monster job.

It had the abs sensor changed due to abs fault, bit after fitting, vagcom is throwing up tons or errors:

abs sensor impluasible signal (still)

Abs control unit no signal intermiittent

Engine control module no signal intermitent

The speedo also stopped working, power steering light off and on and petrol gauge off and on even with half tank. Its also going into limp mode & idling like a dog.

My mate is at his wits end, could the ecu be knackered?

Looks more like a can-bus fault to me, possible gateway issue.

Without a full scan or seeing the car its difficult to say. Have you cleared everything down?

Could be a few issues, if it's idling bad could just be a coil pack or injector, both common but so are cylinder leakages.

The only fault beforehand was the abs sensor fault. The car had new console bushes & abs sensor fitted and after that it all went pear shaped.

Ive reset all the fault codes but they appear again after a few mins driving. Can bus fault maybe, I will suggest he checks all the wiring. Thanks for the advice

I'd put my money on a bad earth (or possibly bad power).

The fuel gauge has its own wire direct to the dash insert. It gets its power from the dash insert and it gets its earth from the sender earth behind the dash.