# O2 sensor codes and tuning



## Ponyboy (Feb 26, 2011)

I installed new LTs and mids and the GTO is throwing P0036, ''56, '141, and '161 which are all O2 related. I deleted the rears but the fronts are plugged in. Do I need all 4, just the front 2, or none? I have HPTuners available to me which can be used to have them tuned out, correct? The front 2 are new sensors so I'm not sure why they're even lighting up.


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## danfigg (Sep 27, 2009)

*re*

well if you didnt tune the car after the LT install that may be the problem. A hand held tuner or dyno tune will probably be needed. Does the car still run good after throwing those codes or did it cause a driving issue. Sorry i cant help but I just bought a used set of Dynotech longtubes with the catted mids and the 02 sensors are in them. They are off an 04 and I have an 05. Will those 02 sensors work. I searched for part numbers and it say that both upstream and down stream 02's are the same for 04-05-06 GTO's but I read an American racing header install that says all 3 years are different for 02's-danfigg


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## Ponyboy (Feb 26, 2011)

Car is going to be tuned for sure. I have a cam to put in as well so I'm waiting until that's done first. I meant for best performance once the car is tuned, are the front two needed or not, and whether the codes can be tuned out completely or will I always have the light on if I'm not using some of the sensors. (Pacesetters LTs w/ cat-less mids)


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## danfigg (Sep 27, 2009)

*re*

Pony im not a Pro but I think what im understanding is you need the two fronts to work. The back two get shut off. If you just put a set of long tubes on with not tune your gonna throw codes. If you do the tune such as a hand held like the one i have (SLP Predator) You load the tune and I believe it will shut the rear 02" off as they are not needed.....I also found this on another site sound familiar......yes, that's the norm for long tube headers... because they place the O2 sensors further down the line, so they don't heat up as quickly as stock... so they trigger the codes for "slow response/switching"...

need to get the trouble codes disabled via a tune... 
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## danfigg (Sep 27, 2009)

*re*

.Sorry this was the original question. I tried to edit and it didnt work....Has anyone experienced slow switching(response) o2 sensors with LongTube headers and an large cam.....yes, that's the norm for long tube headers... because they place the O2 sensors further down the line, so they don't heat up as quickly as stock... so they trigger the codes for "slow response/switching"...

need to get the trouble codes disabled via a tune... 
__________________


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## Ponyboy (Feb 26, 2011)

Noted. Thanks!


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## svede1212 (Nov 1, 2005)

You don't need any O2s to have the car work correctly. Not using them is called open loop and the fueling gets no feedback from the exhaust. The rears just tell the system the cats are working. Most use the fronts for closed loop fueling feed back. On the bank 1 & 2 sensor 2 (rears) just uncheck the SES light box and make them mode 3-no error reported. That will turn off the rears


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## Ponyboy (Feb 26, 2011)

What are the pros and cons to open or closed? Or is it irrelevant?


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## svede1212 (Nov 1, 2005)

The best IMHO is a modified closed loop in which it just runs on short term fuel trims. I wouldn't run open loop without a wideband O2 gauge to keep an eye on things. That's run off just the fronts and enabled thru tuning.


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## danfigg (Sep 27, 2009)

*re*

So does the wideband O2 gauge take the place of the 02's when running open loop. This is of course someone who has there laptop in the car and tuning. I was on the HPtuner site and found it to be interesting. The credits were confusing but I get it. They dont want you tuning every GTO in the county----danfigg


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## svede1212 (Nov 1, 2005)

I can tune any '04 GTO. It just took most of my purchased credits. Well the wideband is used for monitoring/logging. When I tune my car (SD) I run totally open loop so I can see what the fueling is for any speed/load without feedback correction. The gauge makes it easy to see I'm not running stupid lean while doing my logging. After VE correction (fueling) I put the car back in "Open loop w/short term fuel trims". Basically a type of closed feedback correction but it ignores long term trims and just corrects for the moment.


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