O2 Sensor problem after FI LTH install
 

Yesterday I had Fast Intentions Long Tube Headers installed on my 2011 370Z. Everything went smoothly except for a CEL. The codes I am getting are p0051 (low voltage on the o2 heater) and p1168 (closed loop control function) on bank 2 sensor 1. The car is running really rough and I don't want to drive it until this issue is resolved. I don't see how the sensor could be bad, it unscrewed from the factory exhaust manifold very easily and the mechanic was very careful with it. It was never dropped or bumped into anything.

The mechanic warned me that extending the wires on the o2 sensor was a bad idea. Suggesting that I should extend the wires on the cars wiring harness instead. He said that the solder can screw up the resistance on the wires and cause all sorts of issues with AF readings. I told him to do exactly what the directions said and now I have this issue. My car only has 6,000 miles on it and everything was fine before the install. After some research I discovered that the 2011 370Z uses a different pre cat o2 sensor from the 09-10. I was thinking that could be the issue but the bank 1 sensor appears to be working fine. I have searched and was unable to find any members with the headers installed on a 2011.

After the light came on we pulled the sensor out and checked all the wiring and connectors. Everything looked fine. If anyone has any advice I would really appreciate it. I was going to call Tony in the morning, but I would really like to fix this tonight. It's cold, raining, and my only other way to work in the morning is my motorcycle.

I got your pm and replied to that for you.

We send out 8 high grade, high temp. color coded wires with the headers.

-4 Black
-2 Blue
-2 White

They are already cut specifically to length and the instructions state specifically to only lengthen (1) original wire at a time. This way there can be no mix ups or wire crossing. Now I am pretty sure that you bought the headers used so i do not know if you have everything you need with them.

I have over 90 sets installed between the 370Z and G37 coupe and this is the first time I have encountered this. From the 2 codes your car has thrown, I am almost certain the mechanic that lengthened them did something wrong. Even though the (sensor probe itself) on the 2011 is different, that will not effect the outcome. As long as the correct wires are soldered back together and the correct wire is used, you should not have any problems.

I will be in the shop @ 8 am PST. Give me a call whenever you like and I will help you the best that I can. I am sure it is something that can be corrected somewhat easily...

Thanks, Tony

No offense whatsover but I would be looking for a new mechanic to work on your ride. From the sounds of it I would look over my header bolts too.. Good luck and hope you get it running right.

I'd start with resetting the ECU but after that I would check the lengthened wires to make sure they are securely soldered and wrapped. Sounds like a simple signal issue. FYI you are always going to throw codes with LTHs. Get a tune to disable them if you don't want it (that is what I did).

This advice is not (entirely) correct. Good advice in the first part of what you wrote as far as inspecting the wires.

On the second part you are not correct. You should not throw any codes with our headers. When installed properly, there should be NO CEL light or codes.

Thanks, Tony

Scott,

Thanks for the call this morning. I am sure once the wires are taken apart and then soldered back together you should be fine. Since it is an issue only on one side, I am quite certain it is just an installation issue.

Call me back if you need anymore advice.

Lastly, I look forward to getting your exhaust out to you so you can enjoy it with our headers...

Thanks,

After another phone conversion with Tony I believe we have solved the problem. The mechanic used an impact to remove the demon bolts and the vibration destroyed 2 of my o2 sensors. :facepalm:

Thank you so much for all the help today. I can't wait for the catback to get here.

I will overnight those new wires out tomorrow. You live and you learn man. I had to learn the hard way a while back for the same thing. I ended up buying that customer a new sensor. As we all know, they are not cheap for this car!

Tony

So I assume the solution to this is to pull the O2 sensors before you start disassembly?

You do not need to pull the manifold sensors before you remove the stock cats. You just cannot use impact tools on the cat bolts. I never do for this reason.

When I install the headers I pull the sensors after I remove the cats. I find the front sensors easier to get to with the cats out of the way.

Thanks, Tony

This my friends in excellent customer service.

OP
GL solving your problem. Sorry you have to get new 02 sensors.

After 10k miles on my headers I just through the same codes listed below. Tony how should I go about fixing this issue?

That is not a good thing. Scott982 explained to me on the telephone that power tools were used during the removal of the stock cats. We determined the power tools destroyed the front O2 sensors from the vibration they created.

He purchased 2 new front O2 sensors and has not had any issues since!

Please do not hesitate to call me if you have any questions...

Thanks, Tony

How do you test for a bad sensor? Will there always be a cel light?

Most times more than not there will be a CEL light if you have a bad sensor.