2002 Chevy Impala Turn Signals

If you haven't gotten your answer yet all you have to do is replace the hazard switch located on the dash.

I had the same problem. The right signal would begin to flash very quickly as if the bulb was bad.
I changed the bulb and it was ok for a few days. Then it started again. I would take out the bulb, put it back in and again it would work for a few days. I even bought some of the contact gel and put that in the socket and it would work for about a week and then act up again.
Finally it dawned on me that the right blinker had one distinct difference from the left one. The rubber dome that covers the back of the headlight was cracked and broken up. I bought a new one and put it on about a month ago and knock on wood its been fine since