Flaky Left turn signal & CEL problem

Just bought a 2000 3.4L Tacoma, and a couple of minor things seem to have just cropped up in the last couple of days. Hoping you guys can give a little help here!

1) My left turn signal is a bit flaky. When I push the turn signal lever down, it clicks really fast (like there's a bad bulb, but all bulbs are good) and none of the blinker lights go on (including in the dashboard). If I give the lever just a little nudge up or even put just a little hand pressure to it, the turn signal works normally though it tends to want to go back to the no-op state. The right turn signal is fine. So, it seems the switch for the left is just a little worn or dirty or something. Or maybe its a relay problem? Has this happened to any of you, and if so, is there a quick and dirty fix, or do I have to get a new signal lever? This is kind of time critical, as I don't want someone to plow into me while I'm at a left turn!!

2) My check engine light came on 2 days ago. I just had it scanned this morning and the guy said the problem was from the catalytic converter (sorry, I forgot to get the code number from him). He said this error code is commonly due to using a poor quality gas (I've only filled it up twice, both times with Valero gas). He suggested that I use higher quality gas (with Techron) like Shell or Chevron, and that will probably clear up the problem. Does that make sense to you? Do you all use a pricier gas like Shell or Chevron?

 

1. you can take the shroud of the steering wheel column(iirc 1 small phillips screw on the bottom and 2 larger phillips directly behind steering wheel) and check/clean contacts(compressed air, wd40, etc..) and if still faulty, wrecking yard or ebay a new switch.
2. there are a few codes for cats, code numbers are important, instead of stabbing in the dark. ive never heard of gas tripping a cel unless its diesel or turtle pee your fillin up with, but for amusement, try 91 n reset cel.