Loss of Power

[Bagman]

Seat Lean 1.6 diesel 2016.
1st problem engine management light came on. This was found to be the glow plugs took it to Garage 1 job done.
Driving the next day on a longish trip the emission light came on this went out on the return journey however another engine management light came on.

I took my car to garage 2 ( as a more convenient distance I realise I should have gone to garage 1 as they had done the initial work)
He plugged car into diagnostics and it came up with loss of power ( he was short on staff due to covid).
Picked my car up and now the car will not go much above 25mph , all he done was plug in for diagnostics

Took it back to garage 1 and they have struggled to get to the bottom of it so they have had an auto electrician out.
He said it could possibly be the neutral sensor that has something to do with stop start .
He said the fault comes back as 5v reference fault meaning it could be any of the sensors.
So up to now they have replaced neutral sensor and DPF sensor.
Auto electrician recommends removing the ECU to send off to see if the fault lies there..

Any ideas, I'm sorry I don't have much knowledge of cars I'm sure you can tell with my rambling post.

Just wondering if anyone has had similar problems.

Or knows of any recommended diagnostics in Cheshire.

 

[Woody_72]

Northwest Vagtech in Runcorn are very good. Only do VAG stuff so lots of knowledge.

 

[Bagman]

If I were to pick my car up now and move to another auto electrician is there any legality towards paying for his work?
I understand I owe the garage for parts they have fitted so far they have fitted a dpf sensor and a neutral sensor.
But the auto electrician may have done a few hrs work but is not getting to the bottom of it..
I may possibly be better picking my car up and going to another auto electrician.

 

[Bagman]

Any chance my loss of power could be to incorrectly fitted glow plugs