rich

G112 is on the front or back of the head. The splices are in the harness so you would need to peel them back. Don't have the daigeam here but if you do check the resistance in the complete circuit. From pin #.... At the pcm to the ground at the o2 sensor wiggle the harness and check grounds to see if the resistance changes. Also if the down stream o2s have been tuned out you could attach a ground to that sensor ground wire to feed a known good ground to the circuit. Then see if the problem is still there. This could be faster than chasing a gremlin. If it solves it then look for the real problem. If not. Back to the drawing board.

LS6427

iTrader: (2)

Thanks. I'm gonna have an electrical guru check it all out........I'm not electrically inclined.......

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LS6427

iTrader: (2)

UPDATE................

I've been gone for the past 3 weeks for work so I couldn't do anything with the car till tonight.....I just said screw it and bought two new 02 sensors. Took it for a spin and its perfect.
It was probably just the right one that was bad....but I really had to get the car going so I just put two new ones in....I really need the car for tomorrow morning to go out of town a couple hours north.

So....I'm guessing the PCM senses the bad or failing 02 sensor.....tries like hell to correct it...when it cannot....it switches to another mode ???? and lets the engine run perfect.

So why can't we just get rid of the 02 sensors altogether and keep the PCM in that mode ......because when it stops that missing/breaking up crap for that 20-30 seconds....it runs great.

????

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SEMI-RETIRED

I hope you stumbled across your problem.


Proper diagnostic work with the proper tools would be able to find this issue without to much trouble as suggested way earlier in this thread.

edcmat-l1

iTrader: (10)

LS6427

iTrader: (2)

Nobody once told me that ONE bad 02 sensor can make a perfectly good 02 sensor on the other side be wacked out too and throw codes. If I knew that or was told that, I would have replaced that 02 sensor.

BOTH 02 sensors were just 2 months old, so I along with everyone else thought it was something else that was wigging both of them out.....from vacuum leaks to bad MAF to a bad PCM.

But yes.....I should have just tried two new sensors......I was hesitant because they were just 2 months old.............

.

LS6427

iTrader: (2)

Well, I guess something did come out of this that everyone can learn from.......one bad 02 sensor can make the other GOOD 02 sensor throw false codes......they are real codes, but they are false because the BAD 02 sensor was making things run so bad that it was wigging out the GOOD sensor making it throw codes that it otherwise wouldn't. This pointed people to something else being wrong that can make TWO Banks throw codes.......when all along it was just one BAD sensor. And that one BAD sensor was 2 months old, that threw people off a little bit too.

We will be learning about these cars for the next 20 years......lol.....

Thanks for the help with it though......

.

joecar

Thanks for updating

CancerJCC

iTrader: (4)

Your car runs off of hard data referenced by the PCM. VE, MAF tables etc. This data is what the car is "supposed" to be seeing. Your o2 sensors control fueling by adjusting what is ACTUALLY coming out the exhaust. In other words you can run without o2's but small variances in climate etc can't be adjusted for. That is as simply as I can put it. Hope that makes sense.

edcmat-l1

iTrader: (10)

I think what you should learn from this is the importance of scan data. From the initial onset of the problem, if someone would have ran a data log, you would have been able to "see" what was going on, saving time and energy.

I think lesson number two, for you and everyone else reading, is that you can replace parts all day long, and may or may not fix your problem. You lucked out. It could have just cost you another 150 bucks (or whatever the cost of the sensors were) for nothing. This is not good practice, and doesn't make sense.

joecar

LS6427,

I agree with what Ed said... throwing parts at the vehicle can get expensive and not necessarily fix the problem.

You see where this is going...? Wrenches/sockets/ratchets/hammers are not sufficient anymore, you still need those, but...

if you wrench on your own vehicle then a scantool is very necessary...

but also by the same token (you personally wrench on your vehicle), then a scantool will not satisfy you mentally... you really will need to step up to a tuning package;

sure, this will then take up all your time (learning curve) but is mentally very satisfying, and you will learn about engine controls, and be able to make soft mods to match your hard mods;

not only will it mentally feed you, it will allow you to tune and fine tune, and to make alterations alterations as needed when changing parts (or even to just experiment for the sake of learning);

a 21st century carguy can't really call himself a gearhead anymore unless he has a tuning package that he has learnt to use and uses regularly... a tuning package is very necessary (it's an extension of your toolbox).