This study presents the design and development of a Post-Ignition Exhaust Purge System (PIEPS) aimed at reducing exhaust emissions, improving exhaust cleanliness, stabilizing oxygen sensor feedback, and extending catalytic converter service life in both petrol and diesel engines used in automobiles and generators. The proposed system incorporates a high-temperature-resistant air nozzle placed between the oxygen sensor and the catalytic converter. The nozzle is connected to an electric air pump through a flexible heat-resistant hose. Once the engine is switched off, the ECM activates the pump for a short duration, directing clean air through the exhaust pipe to purge residual gases.

Experimental observations demonstrate that controlled airflow effectively removes trapped exhaust gases, reduces carbon buildup, and decreases exhaust backpressure. Consequently, the oxygen sensor produces more stable voltage signals, contributing to improved catalytic converter efficiency and extended durability. The purge action preserves the effective volume of the exhaust system, reduces cold-start emissions, and provides significant benefits for older vehicles with degraded emission-control components. Due to its low installation cost, component compatibility, and ease of integration with existing systems, the PIEPS concept offers a practical retrofit solution for regions with aging automotive fleets and emission-related challenges.