hunts at idle, very up and down but sort of clears then comes back

So had a bit more of a look at this c3. I changed the purge valve which cleared it a little but still up and down on idle. Plugged diag and it actually got some codes which were -

P0105 MANIFOLD
P0110 INTAKE
P0120 THROTTLE PEDDLE
P0440 EVAP
P1280 MULTIPLE

I did drive it a short distance with another purge valve. The power doesn't gradually come it suddenly drives and it cut out. Getting a bit stuck with this now.

Mrtom1973 wrote: ↑Sat Oct 10, 2020 9:33 am So had a bit more of a look at this c3. I changed the purge valve which cleared it a little but still up and down on idle. Plugged diag and it actually got some codes which were -

P0105 MANIFOLD
P0110 INTAKE
P0120 THROTTLE PEDDLE
P0440 EVAP
P1280 MULTIPLE

I did drive it a short distance with another purge valve. The power doesn't gradually come it suddenly drives and it cut out. Getting a bit stuck with this now.

Codes are good. It gives you a place (or few) to look at.

Best thing to do with codes is read them, clear the ones that will then drive it. Take a new read and the ones from the new read will be only fresh or permanent faults.

Your code reader doesn't seem to give much information, a working lexia clone tool (information topic) will give the full description and often a fault diagnosis tree along with the ability to monitor live data for the faults.

I would, using the fresh codes, work through them one by one, finding common points as I go, reading live data to see if the signal is getting through and checking for the citroen faults help in lexia to do the checks they suggest (if any).

P0105 MANIFOLD and P0110 INTAKE are from you disconnecting the MAP sensor.
P0440 EVAP:- That's from the purge valve. One of them (of the two that you tried) might be open circuit or you ran the engine with valve not connected.
P1280 MULTIPLE unknown. Propriety code.

P0120 THROTTLE PEDDLE: It's unclear if this is the throttle peddle in the cabin or the throttle position sensor on the engine. I have conflicting data from the internet as to what P0120 is.
Have you taken the air filter box off the throttle body and looked a the butterfly valve? See if the butterfly valve is moving by itself.

Have you taken the spark plugs out to see what they look like?

Mrtom1973 wrote: ↑Sat Oct 10, 2020 9:33 am The power doesn't gradually come it suddenly drives and it cut out.

Can you rephrase this statement? Does the car just "take off"? Or it lacks power and then goes?