GC4P 1.6 THP 5GZeng. Injection time differs

[renel]

I got a new used car now and I did changed my profile. SN: VF7**************[VIN obfuscated, can be read by forum staff]
I got 2 dtc's: P306C and U1318 86, both are cleared for the moment but I see on my tester that the Injection time differs: cyl. 1-3 are around 0.6-0.97 (flickering a little) but cyl. 4 is around 2.27-2.57, I can see on the internet that there are explanations telling that this can be deliberate for a reason, which I dont understand;-), could that be so? I do have a dtc though so I guess not.
Add. info, I have had a O2 sensor problem, it seems to be resolved with a new downstream sensor.
I am afraid to go on longer trips because I get both engine and electrical failures repeatedly (all well known inhere I think ) Otherwise a lovely car.

[mickthemaverick]

What year is the car?

[renel]

It is a 2015 model at 225000km on the clock. Add. Q. could it be a wrong electronic signal ( from other sensors) on a good injection nozzle, or a defective nozzle where the electronic tries to compensate to makeup?

[renel]

Also, I know that cyl,no,1 normally is at the flywheel end, but on this one PSA/BMW engine I am not sure, if same engine is in BMW then it might be at camchain end?

[renel]

Does anyone just know where cyl no 1 is on this 1,6thp 2015, since when my tester say cyl 1 so and so data, It would be good to be sure if it is the usual Citroen way or "the german way"