Hello All,
i need your advices on my actual issue with my R53 (132k km, 550cc bosch, modified injector connectors, E85 prog, 15% pulley, cold spark plugs). Bought it last month, drove it to my home (500km) but not without issues : after 1h the car put itself on limp mode (little power, tractor noise), i turned off and on and it was all good. 2h after, got surprised witht the fuel tank indicator (did 250km with the 1st half tank, and after 120km car was saying it needed fuel). I found an E85 at the last minute and i almost put 50l on it. Few kms after, limp mode again, and i did like 70km on the motorway to get back home. I checked the codes once arrived, P302 misfire. The car have a malian exhaust, i dont know which model, but it's very loud and in idle with the error codes you can hear a lot of pops.

What i did after :

Compression test : ok
Spark plug check : ok
Coil pack + spark plug wire changed.
Fuel pump + fuel filter changed.
Switch injector 2 to 3 and 3 to 2
And now i have :
P304 misfire

I don't get it. Can it be the injector wiring ? the EV6 connectors replaced the original EV1 and the wires have been soldered + thermo sleeve. Can it be something else ?

I didnt put the car in a repair shop because they are all full nearby, and waiting time is +1 month minimum.

Thanks a lot in advance for your help !