O2 Sensors Issue and Warning (pics)

SS_Firehawk

So I've gotten a small bit of bad news about my build and I'm trying to understand this O2 sensor issue that's going on. I added pictures below that I received from GTM. So I knew our cars came with a pre and post cat O2 sensors. I know for sure the pre cat O2 sensors cost more than the post cat sensors. I understand they do more than just help determine AFR, but I don't have a complete understanding of why the fronts cost twice as much as the rears. In 2011 Nissan changed the front O2 sensors, and the price doubled. Looking at this damage, I may have to replace all four sensors because of an improper install before GTM got it. What makes this more infuriating is I told the shop not to mix them up, removing them before using an air tool on the headers, and to extend the wires one by one. This has been a headache I was chasing for over a year. I had one pre cat sensor replaced because I saw it reading crazy, but seeing that all four were jacked up, pre cat O2 sensor in the J tube, post cat in the free stream, jacked up wiring, melted and shorted at that.

So just a warning... If you are doing a header/ TP install yourself or at a shop, label your sensors so when you put them back in, you don't put the fronts in the J tube and the rears in the free stream. Extend one wire at a time, as there are two black wires. Don't use an air tool to remove the O2 sensors, or on the headers/cat until the sensors or off or risk damage. Removing the O2 sensors period can be difficult without damaging them, so be prepared to spend extra on replacing them. I can't stress how anal I was with the shop that did this, but in my own ignorance, I can't visually tell the difference between the two sensors. I even checked to make sure the wiring was up and away from the headers to prevent melting. I obviously still failed. Now I'm well over $1k out of pocket just to fix something that should have been right from the start.

If you are troubleshooting, there will be trouble codes, but sometimes hard to determine as some trouble codes can be cause by multiple things. I did get a P0300 and P0172. The sensors were reading very erratically from one extreme to the other. My gas mileage tanked to about 15mpg, as the ECU was dumping fuel into the engine as a safety net because it didn't know wtf to do with the AFR readings it was receiving. GTM saw the fuel trims were erratic as well. Hopefully this helps anyone else who may come across this issue

FYI, this is an excerpt of GTM's email on this problem.

""As you know, your car has a CEL P0300 and had that code when it came in. We took a peek under there and noticed that the previous shop had put the primary sensor in the J tube instead of the freestream bung. We switched them around and there was no change. It looks like the previous shop extended the wrong O2 sensor wires. In addition, the wires appear to be crossed which melted and shorted the wiring. You will need two new O2 sensors as well since they were shorted out. Because the O2 sensor wires are shorted, there is a small chance that may have damaged the ECU so we need time to diagnose your car and check the ECU. I have attached some pictures of the wiring and O2 sensors so you can see what we're talking about. Overall, we need an additional 5 hours for diagnosis, repair, re-wiring, checking the ECU, and replacing the 2 O2 sensors plus the cost of two new sensors."

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Chuck33079

Oh that sucks man. Any chance of any cooperation from the shop that ****** them up?

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2011 MB Touring-Sport-6sp-Nav/GTM TT/FI TT TDX/JTran/Kosmic/Eibach/Hotchkis/SPC/CSF/RPS/SoThatsWhereAllMyMoneyWent

Z-Girl 12

craaaapppp....that so sucks. sorry

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2012 Z-SOLD
2014 Nismo #565 Fast Intentions CBE/HFC/Swift/SPC/RJM/H&R-15/20mm/Z1 CAI/Headers/Intake Manifold w/Uprev Tune 328.31whp/263.64tq

SS_Firehawk

No clue yet. I also edited my original post with codes and what to look out for.
I will talk to them when I get home. They aren't bad guys, and don't hold animosity towards them. I didn't get charged a lot for the install and I know they were very careful with the vehicle, but when something like happens, it's hard to look over it. I'll keep using their dyno, but I'll have another shop do the work.

Edit: And this pretty much explains why my numbers were so low with all the boltons I had. 310/241 STD on a dynojet. It seemed like I should have been higher, 15-20 more on both whp/tq at least. If you look at my journal, in retrospect, look at the dynographs taken. They aren't smooth like my stock one, even after tuning. Not only that, compare them to other bolt on graphs out there, tuned or untuned. It shows a lot.

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Chuck33079

Yeah, they really can't say much when you hit them with those pictures.

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2011 MB Touring-Sport-6sp-Nav/GTM TT/FI TT TDX/JTran/Kosmic/Eibach/Hotchkis/SPC/CSF/RPS/SoThatsWhereAllMyMoneyWent

MyKindaGuise

Bro, Im so sorry. GTM may be right about the ECU.

I had a similar experience about a year ago. I had a "friend" from a Nissan dealership help me with my header install(this is what forced me to learn to do my own work...with some actual professional guidance) and he did a similar thing.

When he extended the wires he crossed two of them and fried the ECU and both AFR sensors. It was $2600 to fix. I hope your ECU is alright dude.

However I have mixed feelings about this.

I have talked with two GTR techs now and they say they see similar stuff on non modded cars. In fact one just got a brand new untouched 2013 Altima coupe that had one of the sensors go bad and fried everything. I think Nissan may have an issue here but it isn't common enough to chase.

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MKGs-Single-Turbo

Rusty

That sucks. Feel bad for you. Been tellin' people about not using a rattle gun on the exhaust for along time now.

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Elmo370z

That picture. Is that what your talking about crossing the black wires?

Rusty

Yep. Also you should soldier the wires and use a shrink wrap over the joint.

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"The Difficult Anytime, The Impossible By Appointment Only"
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Elmo370z

Done.

Elmo370z

My buddy has a soder