Erratic acceleration - help

I have a 98 ford contour, SE, V6, 90000 miles.

At random points in time (at various speeds), during driving, the car starts pulling away and the rpm swings wildly between 2000 & 3000. I can feel the accelerator automatically being pushed and released on its own. This causes the car to jerk wildly. After about 2-3 minutes this stops and the car behaves normally. The check engine light is on and off (again randomly) but not sure if this is related. However, this happens more often when the check engine light is off. I believe there is a “transmission code” that is still to be fixed.

Appreciate any help about what is wrong, as the mechanic is unable to reproduce the problem and so can’t fix it.

The first step is to have the stored trouble codes read.
Nobody, whether it is a mechanic on the scene or someone thousands of miles away in cyberspace, can diagnose this without the codes.

Go to Auto Zone, Advance Auto, O’Reilly, or perhaps Napa to have the codes read, free of charge, and then come back here to post them.

That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P0123) not just their translation into English and post it back here.

could be a leak in a vacum hose, check all hoses for cracks

The movement of the accelerator pedal is something the cruise control would do. If you don’t need cruise control, disconnect it, and see if the problem recurs.

Hi all,
Got the codes read:

p0708 - trans range sensor

p0420 -catalytic convertor

The mechanic suggested that we have to replace the catalytic convertor, and need to unclog…

I had been ripped off by another mechanic sometime ago and am very skeptical about believing this person…

Suggestions / price estimate welcome! Thanks.