1999 Honda Accord ABS and Other Things

Brakes problem
1999 Honda Accord 4 cyl 157000 miles

I have a '99 Honda Accord LX with 157k miles on it. In December it started to have a problem with idling. I live in the Chicago area and the weather was very cold this winter. I would start the car and typically when it was warmed up, the engine would start to rev while it was idling. I didn't have it repaired right away and now the problem has progressed to revving upon starting and it's pretty jumpy/jerky when I'm driving (when foot is off gas). My mechanic said this is due to some sort of filter needing replaced to the tune of $400. Sorry I don't remember the name of the filter.

Problem number two: This weekend while driving the ABS light went on and about four times within a 15 minute span of time my brakes were very iffy. I thought I wasn't going to stop. The ABS stutter did not go off (you know, the stutter that happens when the ABS is engaged), but my foot went all the way to the floor when breaking. My mechanic said he checked all fluid levels, etc. And that I need a new ABS module to the tune of a $1200 repair.

Does this sound correct? Thanks!