main oxygen sensor

[93XLEcamry]

ok so recently, my check engine light came on....i checked it and it blinked twice follow by another blink which correct me if im wrong, but that is 21 which is main oxygen sensor, now my question is, if that is faulty is there any way to fix it via cleaning or is buying a new one my only choice???

and if i do replace it, will it be a job i can do or do i need to take it to the shop to get it done...

[fenixus]

which model are you talking about? 2.2L?
code 21 - main oxygen sensor - that would be the upstream oxygen sensor sitting in the exhaust manifold, right in front of engine. should be fairly easy to do yourself with a Denso OE sensor off amazon or ebay, local part stores will rip you off on it, local mechanics flatten your wallet too.

borrow oxygen sensor socket from autozone (refundable deposit required), get some PB Blaster and give it a try. all you need to do is open the hood, unplug it, remove, replace with new one and plug back in

I assume you have a 3/8'' ratchet or better a torque wrench.
can get one cheap from HFT:
http://www.harborfreight.com/3-8-eig...rench-807.html

[93XLEcamry]

i have the v6 camry does that make a difference??

[fenixus]

yes it does.

i'm not 100% sure but the same code on V6 is probably referring to Bank no.1 which is the rear bank by firewall. Much harder access, basically it's doable from top with car on ground, but you will be working with one hand and some things will need to get removed first, e.g. the intake hose with resonator and such.

Hopefully gen3 V6 owners will chime in and confirm which sensor this code is related to.

Originally Posted by 93XLEcamry

i have the v6 camry does that make a difference??

[93XLEcamry]

so 21 on a v6 is a different sensor??

[fenixus]

it's about the engine bank numbering. the lower code usually refers to Bank no.1 and that is the rear bank by firewall (as it appears when standing in front of opened hood) on V6 while on 2.2L it is the "front" (and only) bank.

unless I'm totally missing something and gen3 have different (and placed in other spots) o2 sensors than gen4 do. sorry I can't help.

Originally Posted by 93XLEcamry

so 21 on a v6 is a different sensor??

[93XLEcamry]

awwww....well i hope its the easy sensor...the main one right???

but before i do buy a new sensor...i read on this forum that there is a ca and an fed sensor...and i know that we are suppose to look under the hood, but if i remember correctly, under my hood is just the fabric covering...am i suppose to remove it??

[fenixus]

there should be a sticker right under hood in a visible place. at least gen4 have those, it says which emission specs the car is compliant with.

on gen3 (depending on year) the emission specs also can mean it has only 1 sensor (older 5s-fe federal specs) or second sensor after catalytic converter (california specs model).
V6 must have at least 2 upstream sensors (and no third one possibly on federal model) while california model will have a third sensor after the catalytic converter.

I'm not 100% sure but I think upstream sensors were same between federal and california emissions specs on gen3.
gen4 use different ones (wide band AFR sensor on cali models vs thimble type o2 sensor on fed models).

If you are unsure which one you have, just call the dealer Parts Counter, give them VIN of your car and ask which emission specs it is and how many oxygen sensors it carries.

Originally Posted by 93XLEcamry

awwww....well i hope its the easy sensor...the main one right???

but before i do buy a new sensor...i read on this forum that there is a ca and an fed sensor...and i know that we are suppose to look under the hood, but if i remember correctly, under my hood is just the fabric covering...am i suppose to remove it??

[JohnGD]

The front of the engine is the timing belt side; the rear of the engine is the transmission side. Bank #1 is on the right, which is the fire wall side, and Bank #2 is on the radiator side.

Both banks (Calif/Fed alike) use unheated thimble sensors, about $50 each (rockauto). The universal type is less, but you need to splice on the old connector. This not a problem, but not sure that's something you want to do.

The downstream uses heated sensor, so that's $65.

[BMR]

I'm not certain, but I *think* code 21 is the front bank sensor, the one in the exhaust manifold, right behind the radiator. It's in plain sight, can't hardly miss it. I'll have to double check that though, when I get home tonite. Unless someone else chimes in who knows for sure.

[93XLEcamry]

yea i thought it says main oxy sensor too, but the thing that im not sure of is the ca and fed sensor...because i checked under the hood just now and nothing i see no sticker of any kind under the hood..so i guess i'll just have to call in???

[fenixus]

have VIN handy and call the dealer Parts Counter to check it for you.
That's what I had to do with wife's 5s-fe as hood was replaced on that car (post-salvage car).
I actually ordered the missing stickers from dealer and placed them under hood where they are supposed to be

You can also ask them what the code 21 is referring to, which sensor exactly

Originally Posted by 93XLEcamry

yea i thought it says main oxy sensor too, but the thing that im not sure of is the ca and fed sensor...because i checked under the hood just now and nothing i see no sticker of any kind under the hood..so i guess i'll just have to call in???

[93XLEcamry]

yea i guess i'll do that, but ill check the codes again to make sure that its 21....because it blink blink then pause then blink....then it repeated...sooo im guessing it is 21, if it is, then ill call in and get more inputs on which parts to get...thanks everyone...

[BMR]

Like fenixus said, my '92 Camry (same engine as yours) with CA emissions takes the same O2 sensors as Federal. Denso's online catalog says the same part number is used for both Fed and CA in the exhaust manifolds. CA cars have an additional third sensor downstream from the cat, Fed doesn't.

Denso p/n's:
234-1053 ($41.45 each @ Amazon) for the "upstream" w/ the plug
234-1057 ($27.95 each @ Amazon) for the "upstream" w/o the connector plug - you have to transfer the old single-wire connector plug by cutting and resoldering it.

If you like to buy at Rockauto, they won't show the 234-1057 sensor in the car-specific listings, but if you do a search for the 234-1057 p/n, they do have it.

[Silent Runner]

Just checked my manual (code21), says: "Main oxygen sensor" (which one not specified), or "Main oxygen sensor heater". darn OBD1, not very specific! Check your wiring continuity first, then replace the front sensor, 'cause its easy, then switch it with the back, cause all the bad stuff happens there, then look into the oxygen sensor heater. Which I've never honestly laid eyes on. Thats the best I can offer.

Code 22 is coolant temperature. BTW.... have you tried just reseting the ecu, by pulling out the EFI fuse for 30 seconds or so, to see if the code trips again?