Hello:

Working with my 1998 Expedition 4.6l. Occasionally, it will exhibit a high idle up to about 2200 rpm in neutral or about 1200 rpm in drive. Seems to only do this when hot. Has about 107k miles on the clock.

I replaced the IAB and it 'seemed' to fix it. Then about a week later - it's back!

The last time it did this, it threw a CEL, code P0122 "TPS Low error" - or something like that. So I replaced the TPS and it was fine for a couple days then - it's back!

When it does this, it is like the cruise control is on. Of course it is easy to slow down with the brakes, but it is very annoying. Sometimes the idle will ramp up and then settle down. Pressing the throttle to WOT has no effect and I have checked all the linkages while it was exhibiting the high idle problem and none are bound up. also manually rotated the throttle plate to the stop and nothing changed.

Anyone had this problem before? Any other suggestions?

Best Regards,
Steve
ttlx