Question about Check engine light?

Hey guy's my check engine light came on the other day. I have a 2003 Tacoma xtra cab 4x4 (auto) with 93,000 miles. Is there any way to get the trouble codes without buying one of those expensive readers?? I took it to a shop that does alot of work on Toyota's and they can't seem to find the exact problem. They said is seems to be the "Heater Circuit" on one ot the O2 sensors. Any Ideas, and is there anyway to test them while on the truck?
Thanks for any help?
George

 

Scanguages arn't too bad better that than buy parts that dont fix the problem. Only $135.

 

Do you remember the exact code?

 

No, I forgot to ask. I'll ask him on Monday.
Thanks.

 

if it's a heater code for the 02 sensor it's generaly the sensor itself .it would be better to know what the exsact code is.if it is the heater code check your wiring and the female side of the terminals for proper tension.and on the scangauge reader i'm not sure if you can get to indepth with diagnosis like reading the sesor parameters.maybe someone that has one can chime in.i have only used make specific scan tools .best of luck keep updating there's alot of people that give good info on here.

 

my cel went off for the first time the other day, so i got my buddy to scan it for me, and it pulled a"heater circuit/02 sensor code. i went and got one from the stealership, and replaced mine(upstream/bank1) and its been good since.

 

Alright guy's I finally got the code. P0031, anyone know what this one is & what do I need to replace?
Thanks.
The code came from the "Scangauge II"

 

i believe that the upstream o2 sensor code...same one i had.

 

this is what i love about tw..... =D