What causes air leakage at one corner of the screw on the three-way catalytic converter gasket?

[VonAllie]

Air leakage at one corner of the screw on the three-way catalytic converter gasket may be caused by the screw not being tightened properly or the screw being damaged. Below is relevant information about the automotive three-way catalytic converter: 1. Working principle: When high-temperature exhaust gases pass through the purification device, the purifying agent in the three-way catalytic converter enhances the activity of CO, HC, and NOx gases, promoting certain oxidation-reduction chemical reactions. CO oxidizes into colorless, non-toxic carbon dioxide gas at high temperatures; HC compounds oxidize into water (H2O) and carbon dioxide; NOx reduces into nitrogen and oxygen. 2. Consequences of damage: If the three-way catalytic converter is damaged, the secondary oxygen sensor on it will not be able to correctly provide data to the engine control unit, leading to either excessively lean or rich air-fuel mixture. A lean mixture can cause ignition difficulties, lack of power, engine backfiring, etc., while a rich mixture can increase fuel consumption, incomplete combustion, severe carbon deposits in the cylinders and spark plugs, etc. The engine fault light should illuminate when such faults occur.