The throttle body may accumulate an oily, black residue in the bore and on the throttle plate causing hard starting or possibly stalling when coming to a stop. The throttle body should be cleaned during regular maintenance but do not spray cleaners directly on or at the throttle position sensor (TPS) as this can damage the sensor.
Car Problem Reports
Jeep Wrangler Engine Performance Problems Due to Residue on Throttle Bodies
Jeep Wrangler Problem
Exhaust & Emissions Affected: 2.5L 4 Cylinder, 4.0L 6 Cylinder
Average Mileage: 166,500 mi (90,000 mi - 243,000 mi)
Visitor, 2003 Jeep Wrangler, 90,000 mi
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