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O2 position sensor location code question

WEJOXJ

WEJOXJ

NAXJA Forum User
Location
Utah
Going through my Haynes manual right now and of course there are seperate codes for each of the O2 sensors but the position code isn't clear to me-i.e. 2/1 or 1/1.

I am thinking 1/1 is the closest to the block and the 2/1 is the one after the catalyst. Is this right or am I backwards?

Thanks.
:helpme:
 
Nevermind, think I figure it out. Didn't see a question quite like mine in the search, so....

Think the first position is the bank 2/1 would be for bank 2 position 1 (pre cat), ah crap, or do I have this reversed?

Having one of these again is like learning to ride a bike again.
 
Do you have a 00 or 01, Im pretty sure Bank 1 position 1 would be the upstream on the first 3 cylinders and 1/2 would be the downstream on the first 3 cylinders, took me a while to figure it out when i had codes when i didnt have the downstream ones connected
 
What specific code is it throwing? According to my FSM there are quite a few codes depending on the nature of the fault.
 
I think it should be bank 1 on both sensors, if i'm not mistaken.

Bank 1 Sensor 1 would indicate the pre cat sensor
Bank 1 sensor 2 would indicate the post cat sensor

I see the 2nd one a lot on mine, so I know for a fact on that one that Bank 1 sensor 2 (or 1/2) is the post cat.
 
I was off, way off. Diagnosis was a P0302-misfire on cylinder 2. Which per the suggestions on the ticket raises a load of other questions before going into my haynes manual. Ticket suggested- 1. faulty coil, ignition wire, plug 2. high or low fuel pressure. 3. Faulty injector. 4. Vaccuum leak.

I know it's not low pressure, firing up just fine. If I had to bet thinking plug or coil. Probably go out and do the plug test the unsafe stupid way, the shock is overrated!!
 
I am a ways removed from this stuff and need to get my knowledge back up. In theory it's hard for me to imagine that high fuel pressure would either cause a misfire at all/or on just one cylinder.
 
Crap, it's a 2000
 
Pulled the #2 spark plug, seems to be fresh caked oil/gas almost bridging, just a bit though. Looks like signs of heat fouling, plug seemed cool after running it after 3 minutes.
 
Install a new spark plug, and see how she runs...if you think you have a cylinder problem, check compression...if the problem goes away and stays away, change the rest of your spark plugs..
 
Thanks McQue.

Can't do the spark plug test the stupid way, just boots connecting, no wires. My gut tells me that the pack needs to be replaced, just don't want to. Do the plugs first of course. You're all thinking, stupid just put the DVOM on, yeah I lost it in one of my moves. It's more funnerererererer to just gamble.

Can I call you M, like the Bond movies?
 
Alrighty, I have one more step to take here, and am wondering if this is going to be the last one. Went to autozone, bought plugs to check, disconnected battery (improper procedure I know). Start XJ and wow, spark plug in the #2 hole is going nuts. Which means....? Dry cylinder, need to replace injector? Or move forward with ignition rail thinking it's just timing? There was no sound before and now, it's like I am putting 10,000 volts through. Ideas anyone? Injector, ignition pack, something else?

:explosion
 
....and I now have a bit of oil smoke coming from under the hood.
 
Can you be more specific than "going nuts"? What sound is it making now? You are putting about 10,000 volts through it now that the gap/fouling issue is fixed. Does is sound like you can hear the spark jumping a gap? Maybe the coil has a crack and it's jumping across. That would certainly account for the misfire and fouling. Did you closely inspect the coil?
 
The coil seems to be okay visually from what I can see, which doesn't always mean something certainly. The clicking is definitely voltage going through and not always consistent. Rough estimate is 25 fires, miss 2, 10-15 fires miss 2, 25 fires and repeat of above.
 
Think I got it, thanks everybody.
 
Alright, code is cleared, must have been a poor connection or something. No cracks. I am getting very poor gas mileage now and I guess will go through O2 sensor, tps, iac, and maybe even the cat. Driving down the freeway, it's almost like I am hitting a hill with a gear down without shifting. Soon as it comes it's gone. Getting 12 mpg with no codes.
 
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