U3878 Engine Code Repair

Meaning of U3878 engine trouble code is a kind of network trouble code and theoretically you can drive for a few weeks or even months with a broken MAF sensor. You will notice a decrease in gas mileage and over time the car will eventually start stalling a lot. At a shop, the replacement cost is between $240-$400 depending on the car, but that's usually the cost of parts because the labor is relatively simple.

U3878 Fault Symptoms :

U3878 Possible Solution:

Excessive air inflow can be caused by a vacuum leak, a dirty sensor or, an exhaust gas recirculation valve not closing properly. If the problem is not enough fuel, the culprit may be dirty injectors or fuel filters, a weak fuel pump or a leaky fuel pressure regulator. The lean fuel mix error may be accompanied by rough idling, engine misfires, hesitation during acceleration and overall poor engine performance.

U3878 Code Meaning :

Regarding the U3878 code, it would probably be worthwhile to carefully inspect the wire harness near the intake manifold bracket. This is done most easily from below the car in the area near the oil filter.

Parts or components should not be replaced with reference to only a U3878 DTC. The vehicle service manual should be consulted for more information on possible causes of the fault, along with required testing.