Here is the weird situation: My original MAF Sensor was obviously problematic so I replaced it with a second-hand (since it was 1/5 of the price of brand-new one). All problems were gone, however engine fault light was on. Fault code P1103 MAF Sensor In Range But Higher Than Expected. So I thought it's probably because of the second-hand sensor, got another from the second-hand store, replaced it. Everything was the same. Original MAF Sensor - traction was very bad, but no fault lights are on Second-hand MAF Sensor #1 - everything is good, but fault light is on (P1103) Second-hand MAF Sensor #2 - everything is good, but fault light is on (P1103) Possibilities: 1- Second-hand sensors could be faulty but working sufficiently, but it's not likely that both are at the same state (that is, working properly enough to run the car with no apparent defects but also faulty enough to turn engine fault light on) 2- Second-hand sensors are not 100% identical to the original one. Although the seller said that he has sold many of these for C3 16V models, and none of them were identical to the original but they all worked fine, that could be the problem 3- Something else could be wrong (connectors, etc.) Maybe someone else experiences the same problems in the future, that's why I'm writing it in detail. I will take the car to the Citroen Authorized Service on weekend.