I have a 2005 Tahoe. Today the check engine light came on. The error code is 446. What is most likely to cause this error code? Local dealer to me to check the gas cap, it may be loose. But it was on tight.

 

Advance Auto will usually plug in a tool to pull your code free (the # part) then they usually walk you inside to look up what the code means, it hopes you buy parts from them.

I had a check engine on my 04 Rubicon (my baby that is so carefully taken care of, I paniced)...

"ocassional misfire, cylinder #4" was what the code turned into.

I bought a full set of plugs (why not do all at once; it had 30,000 on it)

ta-da, now it starts better, idles smoother, and is a happy jeep again

Pep boys might do this too; but I find the people at AA usually nicer... (i am not speaking for 100% of them, lets not get into something here)

 

Im guessing its P0446 not just 446.
I'd check your gas cap, then check the vent lines to the evaporative canister making sure none of the lines have been pulled off, knocked off or cracked.

 

Evap canister and solenoid had to be replaced. This was a $350 expence.
Now I noticed the 3rd Brakelight is out. Where can I find a 3rd Brake light for a 2005 Tahoe with a liftgate?

 

Is the 2005 thrid brake light LED or bulb?

 

The 05 Hoe has the LED 3rd brake light.

 

Well here I am again pimping for www.1aauto.com
but they really do have easy to find parts....
try this link

http://www.1aauto.com/1A/TailLights/...TL00892/861822

 

looks like you can get the factory or OEM part also