P1135 code

I have a 2002 Toyota 4-Runner Limited 4WD w/ the V6. It has just over 82,000 miles, and my CHECK ENGINE, VSC OFF, & VSC TRAC lights came on while I was driving today. I got the computer code for P1135, an Air-Fuel Sensor Heater Malfunction. What does this mean? Would this be something that can be fixed by replacing any sensors, or should I take it into the dealership?
It recently just started squeaking and now shakes a little while I'm braking. I was going to take it into the dealer for this because the brake pads have plenty of life still on them. Do you know what could make it do this?
Thanks for any help!

I hate to start out with my first post being a problem, but there it is...

I have the same problem on my 2002 4 Runner. It's 2WD, about 37k miles, same symptom: CHECK ENGINE, VSC OFF, & VSC TRAC lights are lit.

tia, Lee

edit: Nevermind - I didn't search enough - on my way to Mr T parts - so he can empty my wallet

REPLACE THE SENSOR ON THE AIR INTAKE HOSE. IT'S BETWEEN THE AIR BOX AND INTAKE MANIFOLD.

rakesh,

thanks for the input, but it was the O2 sensor (actually they call it something else on the 4_runner) that went bad, replaced it and all is well.