Funny. Got same problem last week ,but with DFGT pedals
First I thought It was 1.09 update ,that scr**** sensibility settings for pedals , but then I've checked with GT5 and PC/LogitechProfiler and pedals were ocassionaly sending random signals for brakes and after a day also for throttle .
Done some gOOgle and found out it is called "spiking". In short ,either there is a short connection somewhere in (broken cable, bad connection somewhere in pedal housing , dirt ...) or more likely one of pedals (ussualy throttle) gets a bit loose and that can cause potentiometer in the housing to perform autocalibration all the time in consequence it doesn't know anymore when pedal is fully pressed/depressed .
I've opened pedal base ,done some cleaning ,checked contacts and pull a wire 1 - 2 cm into the housing to make wires more loose > originally wires were really tight and since I've experienced those spikes mostly when I was pressing foot on the pedal base , I suspected there may be base flexing>bad wiring problem.
In my case doing this helped and pedals are now working with no prob as new.
Usefull link : http://web.axelero.hu/mozso/momo_e5.html# > that's for momo pedals ,but you'll get idea what can go wrong ,since most pedals use similar design .