I just pulled the code for my check light and i have code 21 saying that i have a heater or main oxygen sensor. i dont fully under stand what this means and how to fix it any help?

 

I pulled the same code when I did mine a few weeks back. As I understand it the code 21 is one of the three things you said above ecu, hot o2, or the hot o2 circuit. Have you done any messing around with any wires lately?

 

no i put my cb back in but it came on before that... so i have no idea what it could be??? any help work thanks

 

cb? what are you referring to the radio?
if so i do not think that has anything to do with your problem

are you having any drive ability issues?

check your wiring, map the wires from the ecu to the o2 sensors, check the ground to the ecu, replace the o2 sensors. it must be one of those three things. this coed only happens on the California models.

mines been running like shat for a while and pulled the same code. I plan on mapping the wires form the ecu to the o2's this weekend when i get some time.

 

Perhaps your O2 sensor just needs replacing? Its prolly a good idea to replace it anyways since its a big killer of gas mileage on our trucks.

 

That was the first thing that i did on my rig but that simply wouldn't do. maybe for 90inworks it would be a quick fix. Easy things first.

 

how much do they run? correct me if im mistaken the o2 sensor is the thing before the cat right?

 

thats right. Should have 2 or 4 wires coming out of it, and bolted into the exhaust pipe.

Checkout toyotapartsales.com for the best prices on OEM parts.

You can get an aftermarket one, but BUYER BEWARE! Low quality taiwan junk will only cause you problems.

 

So this means my truck was made in cali ?
and thanks yall for the help

 

yeah i agree
we definitely have the 4 wire ones due to the California emission standards we have to abide by hahahah.

to be honest mine was about 90 bux each and i bought both of them, up stream and down stream

 

HOLY S*** 90 a pop! i guess ill be living with the check light on wow

 

yeah they are up there. that's what it was at my local VIP but you might be able to find it cheaper where ever you are. but that was the cheapest i could find it

 

wow thats pricy i think ill deal with the light lol now cuz i have the cat hollowed (yall came hate me if u want) adn the flowmaster on it could this be why it keeps going off? it seems to only come on when i cruise in 5th and once its on its on for a while. Then all the suddon bam its off till 5th gear

 

thats fine, deal with the check engine light. Meanwhile, its costing you 2-3MPG. At $3.25/gallon, in about a month it will cost you more money to "ignore the light" than to fix the problem.

But you do whatever you need to.

 

if i had the cash i would fix it but im scraipin' lol at 250 a month plus gas and shot gun shells its close lol so the o2 can effect it that much ????

 

so dont go shooting for a week and starat reloading...haha

 

thats asking alot lol i cant afford a reloader LOL
and i got shoot some ducks to make it threw the week with all the high school drama b.s. lol
gotta love it

 

yes the O2 can affect it that much.

But like i said, if you wanna ignore it, so be it!

 

time to take a loan from the first national bank of dad lol

 

hahah good luck hope you get approved
as far as i know it is the front one you need to replace. that is the heated one if not it could be both still a little gray in that area.