ok so i know that with HPT you can just go into the DTC section and make it so the CEL dosn't come on... but ist the computer still tring to get data from the sensor. Is the sensor used for anything other than measuring cat performance. just becuase the light isnt on dosnt mean that the computer isnt still tring to use the sensors data.
Im doing an exhaust build very sortly and am thinking of just not including a rear o2 at all. but im wondering if this is going to put my computer into a limp mode or some other performance hindering sort of crap.
help me out.
no it won't. it eliminates the use of the 2nd o2 sensor
The second 02 sensor has nothing to do with the engines performance. All it does is lets the PCM know that it is getting a constant, even reading after the cat. If it cycles (bad cat) then it sends the code and you need a new catylitic Converter.
BUT if you MUST keep the 02 sensor and dont want as cat, just go buy a spark plug non-fouler kit (make sure you get the ones with the same thread pitch and size as the 02 sensor. Then drill out one so you can screw 2 of the nonfoulers together, then install the 02 sensor into the back, and put the whole thing in. For some reason people are having luck doing this with no cat and still not getting any MIL light. I dont know how it works, but i have heard that it does.
<img src="http://memimage.cardomain.net/member_images/3/web/831000-831999/831395_11_full.jpg">
i just thought i read somewhere that the 2nd o2 sensor is used not only for monitoring the cat but also in helping with fuel effeciency. and that if I remove the sensor completely from the vehical that crazy things could happen to fueling.
I can turn the light off with hpt but I was just concerned with what else is going on inside the computer dealing with the 2nd sensor and if i unpluged the sensor.
nope nothing crazy happening to my car and my rear o2 sensor and wires are somewhere in the garage i just turned it off with hpt. now i do have a hi-flow cat in my exhaust atm and i plugged it with an old spark plug i found
(our spark plugs wont fit) but when i put the 3in turbo exhaust on i plan on no cat, so thats why i just pulled the wires last time i was workin on it. car runs perfect other than me needing a new tps on my 2.3 t/b
this is good info. i was wondering this same thing.
you could just buy a fakey o2 that sends a signal to the computer, so it has no idea anythings wrong, but you keep all your wiring in tact for if you ever go back to stock, or anything like that. and go to a local speed shop and pick up a plug for your hole, theyre like $5....much better than jamming an old spark plug in there.
^^ im never going back to stock...ever
Im running this car into the ground
I kinda wanted to remove the whole rear 02 and the wiring that went with it, and thats what i think i will do, as long as no problems arise
Someone told me COT makes the computer put in more fuel to try and cool the cat down, do our cars have this??
2000 Camaro V6.
| SLP Loudmouth | CAI Intake | HID's |
someone once told me that you could put the 2nd o2 sensor 12" from the front and it would pick up the same temperature and be ok.
John Benham wrote:you could just buy a fakey o2 that sends a signal to the computer, so it has no idea anythings wrong, but you keep all your wiring in tact for if you ever go back to stock, or anything like that. and go to a local speed shop and pick up a plug for your hole, theyre like $5....much better than jamming an old spark plug in there.
or i can save $5 and not jam the spark plug in there cuz it threads in perfect and works just as good for free cuz it was in a random box of old nuts, bolts, and other junk of my step dads, and ive heard too many people complain about o2 sims... now that may be their wiring or something cuz ive never had one, also since i have hpt and others may you could just leave the o2 in there and turn it off too if u want. also the car is never goin back to stock she has been swapped to a 5speed
The facts:
Turning off the codes does not disable the sensor. The PCM will still try to read the sensor, it just can't notify when it reads wrong.
Most PCMs will make fueling adjustments to raise convertor efficiency based on rear O2 readings.
With the sensor disconnected, the PCM will stick with a zero'ed amount of correction. The PCM only makes corrections when it gets incorrect readings and makes no corrections when there is no reading.
With the sensor connected and no cat the readings will basically average out to zero correction anyway.
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protomec wrote:The facts:
Turning off the codes does not disable the sensor. The PCM will still try to read the sensor, it just can't notify when it reads wrong.
Most PCMs will make fueling adjustments to raise convertor efficiency based on rear O2 readings.
With the sensor disconnected, the PCM will stick with a zero'ed amount of correction. The PCM only makes corrections when it gets incorrect readings and makes no corrections when there is no reading.
With the sensor connected and no cat the readings will basically average out to zero correction anyway.
thank you sir.. thats exactly what i needed to know
the best thing u could do with your rear sensor is cut the wires off at the sensor pull the plug apart and pull out the purple and tan wire put the plug back together and wire the two brown wires to a heated universal 02 sensor along with the black and gray wire from your front sensor assuming your front sensor is a 2 wire.and there u go u have a heated front sensor.
protomec wrote:The facts:
Turning off the codes does not disable the sensor. The PCM will still try to read the sensor, it just can't notify when it reads wrong.
Most PCMs will make fueling adjustments to raise convertor efficiency based on rear O2 readings.
With the sensor disconnected, the PCM will stick with a zero'ed amount of correction. The PCM only makes corrections when it gets incorrect readings and makes no corrections when there is no reading.
With the sensor connected and no cat the readings will basically average out to zero correction anyway.
this information is false. i had just installed a test pipe, turned off the 4 codes for the rear o2 and unplugged the sensor and the car runs like @!#$, and my long term fuel trims and short term fuel trims are in the red going negative on the vcm scanner. my car runs like @!#$, is there a trick to getting it to run normal with a test pipe in place of the converter?
01' Z24 5 speed
422whp/400wtq
T4 Turbocharged
Built LD9
HP Tuners
I don't have a cat anymore, and set all rear O2 related codes to "No Error Reported" and unchecked them in the DTC list in HPTuners, and I have zero issues.
You made a thread about it, why cross-post your issue? Now you have to watch replies to two topics. The problem can't be the rear O2 or that you have a test pipe. You screwed something else up, either damaged the upstream O2, or damaged the wiring to it so it reads solid lean. Most likely a short.
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
damn,that sensor is brand new.
01' Z24 5 speed
422whp/400wtq
T4 Turbocharged
Built LD9
HP Tuners
I aloso have no rear O2 sensor, and no cat. No issues.
FU Tuning
