Golf MK4 multiple fault codes please help

[Bokeh42]

Hello all,

New to this forum. I wondered if you VW experts can help with this issue.

Car: VW Golf MK4 1.6 16v Petrol 2003, Manual

Problems:
1. When I put engine under load eg pull away with hand brake lowing the engine speed (below ~900 rpm; nearly stalling but not quite), the engine will start hunting. When it happens, stepping on the throttle will occasionally bring it back to normal. However, sometimes it does not response to throttle (nothing happens, engine keeps hunting). It will be normal when I restart the engine.

2. High idle (~1000-1100 rpm).

3. Engine management (emissions workshop and engine workshop), EPC and traction control warning lights are on. They come on and off. However, EPC and traction control warning lights would not be on without engine management light. The possible situations of the warning lights are:
a. Engine management light only.
b. Engine management and EPC lights are both on - the most common situation.
c. Engine management, EPC and traction control warning lights are all on - only seen this ~3 times so far. If I decrease the engine speed to make the engine hunting (please see problem 1), the three warning lights will come on immediately.

Process:
The car was drove ok but the engine management and EPC warning lights were on and off frequently. When the lights come on, they always come ~1 to 2 minutes after starting engine and stayed on for 1 or 2 days. I thought cleaning the throttle body might help but after that fluctuating engine speed, high and rough idle, sometimes no response from the throttle pedal……etc were happening. A garage has tried to reset the ECU and it improved but still has problems which are mentioned above.
Moreover, lots of faults have been found. Please see the attachment for a diagnostic report for more details.

Anyone has any idea what could be causing all these fault codes?

Many thanks for any help.

[Bokeh42]

Recently, I noticed the following.

When I turn the steering wheel especially if the car is moving slowly (e.g. parking) and turning steering fast, the revs go lower (in extreme conditions the engine would stall).


If the engine almost stalls or stalls then the engine management (emissions workshop and engine workshop), EPC and traction control warning lights might come on.
After it almost stalls the engine occasionally starts hunting.
After it stalls, the engine will often be hunting if I start the engine immediately.


Any ideas?