1998 duratec will not decelerate - Ford Forums

buck955 · 07-17-2008, 16:37

My 1998 (built at the end of the 1998 model year so may have 1999 parts) with a 24 valve v-6 does not decelerate when you leave off the gas, if your traveling down a slight grade the car picks up speed and hardly slows down on the level. Ive put it in neutral at highway speed and the tack stays at 2400 rpm will even stay faster if you give it gas, very slow to return . idles ok when u stop. killing my brakes Please help , Thanks

SHOZ123 · 07-18-2008, 12:20

TPS sensor or related wring maybe.

Or

TSB 99-12-5

ISSUE:
There may be a perceived lack of engine braking due to the increased dashpot function in the Powertrain Control Module (PCM) calibration on some 3.0L engine vehicles. Diagnostic Trouble Code (DTC) P1138 (Heated Exhaust Gas Oxygen (HEGO) rich) may be appear during KOER. This may be caused by PCM calibration strategy.