2026-10-08 · 5 min read
Mitsubishi Xpander Carbon Buildup Malaysia
4A91 is port injection — intake valve carbon is minimal. The main carbon concern is throttle body deposits at 60,000–80,000 km causing rough idle and low-speed hesitation. Throttle body cleaning at 60,000 km is a worthwhile preventive service. Always perform idle relearn after cleaning. Fuel quality matters — RON97 reduces carbon accumulation compared to RON95.
Xpander Carbon Buildup
- 4A91 direct injection tendency: intake valve carbon deposits after 50,000 km
- Symptoms: rough cold start, hesitation on acceleration, reduced fuel economy
- Throttle body cleaning every 40,000 km helps reduce carbon accumulation
- Walnut blast or chemical intake clean at 80,000 km for heavy deposits