Hi everybody,

I recently installed OBX long tube headers, which are working out fine. Not a bad install and impressed with them so far for the price I paid.

I had engine codes P0131, P0133, 0141, 0153, and 0155 after installing the pipes. With all of these being related to O2 sensors, I ordered new DENSO O2 sensors and replaced the front sensors. I expected rear Heat malfunctions with the rear ones, so I did not bother replacing either.

Now very similar codes are back, if not all the same ones. Codes P0133, P0135, P0141, P0153, P0155, and P0161, with P0141 and P0161 being on the rear O2 sensors, so I don't care. All of these codes with the new O2 sensors.

1. Do I have to install GM (or Bosch possibly, I'm not sure which are OEM) O2 sensors to be sure that they will work right??? Why would they sell them if they didn't work right...ideas???

2. Also, what tuner is it that can be updated off the internet and can "tune out" your rear O2 sensor problems? Anybody have one or have a link for me to buy one?

I greatly appreciate any help that can be offered. I am just running out of ideas now.


Thanks!

Steve
2003 EB Z06

 

You need to check for 12V key on at pin D, and the ground at pin C. You probably have a blown #15 fuse in the underhood fuse block.



Russ Kemp

 

I agree you should check the 02 fuse--I would take it to a tuner--needs to be someone with EFILIVE or HPtuners--they can delete the rear 02's and all the codes associated with them--ALSO you need to see if the front 02 sensors are oscilating---Make sure you havn't installed the 02 sensor pigtails backwards---and plugged the fronts into the rears---A tuner can sovle it--You need to see if the ECM is in "open loop" or closed loop when running----AND If your new headers 02 sensor locations are further back then stock--they may not ever heat up unless you modify your 02 switching points---

 

I did what LG headers recommends when I did my headers. Get new rear O2 sensors and with wire adapter, install in the front locations (they have a higher watt heater in them) then tune out the rear sensors and plug the holes. I used my predator handheld to get rid of the rear codes. It just passed emissions like this 2 days ago in Phoenix. Note: I have ceramic coated all the way to the catbacks, so my headers and O2's stay hot and never throw codes.

 

p0133 and 155 are VERY common with the longtube No cat converter community. I infact am battleing these codes. Changed sensors, everything.

They say the placement of 02's on long tube headers cause this mainly because the longtubes with no cats run so much cooler the 02's dont really get hot enough and causes the slow response

 

He needs to correct the P0135, P0141, P0155 and P0161 O2 heater performance codes first as they may also set the P0133/P0153 O2 slow response codes.

In most cases, the slow response and or the P1133 & P1153 O2 insufficient activity codes need to be set to no error reported with long tube headers & no cats.

Russ Kemp

 

UPDATE:

I went through and checked the fuses under the hood. No problems with any of them as they all ohm out good. I can lift the car and check the voltage on the pins of the harness, but that is a major pain and will likely show a good voltage at that point anyways.

I am thinking that I might follow what GPRACER1 stated about his LG headers. I will contact the company and see what successes they have had with this problem. Let me start with that guys. Hopefully they will have something. I mean hell, it's their product so they better know how to make it a success.

Thanks for chiming in guys. I will check a few more things that you all have mentioned, but for the most part it sounds like dealing with the company and forcing an answer out of them is my best starting point.

I'll update soon as I hear something,

Steve
2003 EB Z06

 

I did the LG Motorsports adapters for putting rear sensors on the front with my Stainless Works LTHs and it solved my code problems. I would recommend GM [Delco] sensors instead of Bosch.

 

I had the slow switching codes on mine. It was my fronts. My rears were already tuned out. I bought new bosche sensors. Problems gone, been a couple of months now....Knock on wood.

 

----AND If your new headers 02 sensor locations are further back then stock--they may not ever heat up unless you modify your 02 switching points---


Slow acting 02's are caused by having them to far back from stock-All you need to do is have the switching points changed to where the closed loop wideband readiing is 14.68 Can be done at home with just sticking the WB in the tailpipe

ALSO-If you don't correct it--Even though your computer is commanding a 14.68- in closed loop- it is NOT what you are getting--It is much richer--something like 14.00 ----- if you are in a smog state it will be pig rich and won't pass-- This is why you need to adjust the switching points--It may be also neccesary to re-do your VE table
I had to do this on my personal C5---It would not pass smog after the header install--I stuck a wideband in the tail pipe and it was 12.3-1 !!
My front 02 bungs were about 21" further back

 

ummm I am not an expert but did stay at a holiday inn once with a bunch of other vetters that were lol.

First off, don't ever try to stick a wideband in your tailipipe man! I don't know who or where you heard to do that but you will never EVER get correct readings from there. Its no surprise your showing a weird 12.3 number.
2nd off, and more likely again, cause you measured if from the tailpipe, your readings are completely backwards to almost every typical stock to headers install-your car will go into running lean! NOT RICH. Your running more air in and out of the car, not more fuel. Common sense. This is why, you really should have your car tuned after a header install. Its not absolutely necessary, but highly recommended for over the long term because if you run rich...no biggie, you will just burn a little more fuel. If you run lean, you risk over time killing your motor.

Always place the wideband 02 upfront as close to the header collectors as possible. NEVER mount them in the 6 or 12 position (read install instructions as some manufactures won't let you install it in other positions as well).

Widebands are very sensitive to where and how they are mounted. By trying to mount even temporary in your tailpipe is not wise, your not going to get the correct readings and if you use those incorrect readings to tune your car...lots of luck.

Hope this helps and gives you a heads up.

 

You completely mis interpreted what i said--No wide band in the tailpipe ? Oh please I can see are not from Calif.--EVERY smog shop here sticks a wideband in the tailpipe to read emmisions--- I'm just trying to help him slve his problem--sticking it in the tailpipe like the smog shops do will give him a close idea of how far off it is---
ANd as far as getting leaner with headers-I've tuned at least 75 cars with headers--Maybe only 10 went lean--they were either shorties or headers with the bungs very near to the stock location--The reason most go rich is beacuse most headers set the bungs in the collector which is further aft---so the computer is now getting false information and it thinks it is lean-so it adds fuelmaking the end result rich--
I hope you weren't thinking I was suggestiing to permanantly stick the Wband in the tailpipe and make ECM corrections--that would be rediculous--I was just suggesting ideas to help him eliminate things so he can go forward
I don't know what kind of WB you use but mine can read it in the tailpipe fine--just as a tool to eliminate things so problems can be solved-----
My car ran a 14.3 AFR---after the header install because the 02's were too farback- 21"--It gave me a staring point---Now i knew i had a problem--Next I hooked up my data logger Instaled the WB in a bung pre cat---and went for a ride--Knowing that it was rich beforehand I knew which PIDS i neeeded to monitor--and correct tha appropriate table

 

I was actually assuming you were doing just that. Putting the wideband in the tail. Don't laugh, I have seen plenty do it and then come on here and be scratching there head, wondering why their tune is so far off.

I run an Innovative wideband. Its super picky and sensitive.

Can't say I ever heard of a car running rich after installing of headers with the stock programming. Lean I have heard and seen, and even at that it was not much.

Each car is different and too each their own. Hopefully the guy gets it all figured out.

I do agree in that I think he needs to buy different 02s, return the Denso's and then install some bosch's or GM's and see if the codes clear. If they do not, give the car to a tuner who will put the wideband in the correct spot and then tune the car so that he knows the air/fuel is dead on plus he can have it tuned and have codes set to on and off or "not report" if they need to be. This way, he gets the tune he will need anyways plus the benefit of getting these codes all cleared up. This would definitely save a lot of time and effort vs him trying to figure this out on his own. Unless he knows what he was doing with a laptop and had a wideband, he would have to go to a tuner anyways. Also to the OP, stay away from mail order or internet tunes for your car, you already have issues that require a tuner to work his magic and adjust the custom tune to all the issues your car is having right now. No mail order tune is going to be able to do that, you would end up going back and forth quite a few times.

Hope this helps

 

Guys,

I had to leave town quickly for a 1 week trip, my apologies for not responding.

Anyways, I received no response from the company so far after only an email inquiry. Anybody have a number for the OBX manufacturers?

Well, this is what I gather so far:

1. Order rear-to-front adapters for the O2 sensors. I spoke with the guys at LG and they said that they have only done this about 4,000 times and it has worked just about every time. I followed their advice and ordered two of them (only $39 shipped). With this, I will move the rear sensors to the front positions and put the front O2 sensors in the rear position for now. If you are experiencing the same problem, I suggest you call them and talk it out. I explained what was going on and they said that they see this all the time. If you are interested, PM me and I will give you the number. They were very knowledgeable and helpful.

2. Tune out the rear O2 sensors, which will actually be disconnected front O2 sensors, just to plug the holes in the exhaust. This might have to wait for a while. My German "tuner", here local, did not know what I was talking about today when I brought it up.

3. See where we stand after that and go from there.


I will post another update once I receive the adapters, about a week from now, and have them installed. I anticipate problems with the rear O2 sensors since they will be dead wrong, but we'll go from there.


Thanks for the suggestions and help once again guys !!!

-Steve
2003 EB Z06

 

Did this to mine and works like a champ ... Thanks for the information !

 

MY BAD---I typed in 12.00 -- I meant 14.00---sorry--dam big fingers--hope that clears it up some-----Sorry to confuse everyone--

 

Does someone sell a kit for the rear oxygen sensors and the adapter?