After changing the engine, throttle and oxygen sensor, the old Jetta still emits black smoke and the engine trembles. I used to think it was the burning of oil, but it is still the case now. ....

Black smoke is generally caused by excessive combustion of gasoline in automobile engines. The reasons are: dirty air filter and insufficient air intake; The carburetor is broken: the EFI car without carburetor may also be polluted by the oxygen sensor in the exhaust pipe, which can not provide correct information to the gas distribution computer. Mohji engine repair agent is recommended. Compared with the traditional automobile engine repair agent, SchMohji contains graphene anti-wear repair components, which can effectively solve the problems of burning engine oil, emitting blue smoke and black smoke.