[TurboDA6]

CEL illuminated today, scan showed P2A00

A few weeks ago I installed JBA LT headers because my OEMs were trashed, big cracks in them.
I have been in the process of e-tuning with UpRev.

Researched this issue online and I am very very concerned because it seems no one actually fixed the issue. I just found a bunch of threads that trailed off...................................................

1. It has been suggested to replace the O2 sensors. But, I don't get a "warm fuzzy" about that suggestion for a few reasons:
-everyone else that posted their P2A00 issues said that new O2s didn't fix a thing.

-I highly doubt that my functioning, 70k mile O2 sensors failed right after install. I actually didn't struggle to remove them, so they weren't "roughed-up" as may happen with sensors that are seized in the bung.

-In my years of working on vehicles, O2 sensors fail by becoming lazy with age or going full-scale output, barely moving when the engine is running. My O2s seem alive and well, the ECU is just unhappy over a period of time that it is unable to correct A/F issues.

2. It has been suggested that their is an exhaust leak. Hmmm:
- I had a massive exhaust leak in my OEMs, big gnarly cracks in both headers, tons of noise. No CEL EVER. Just horrible MPGs (about 10 in town).

- I recently went to an exhaust shop to have my crossover pipe welded and a Vibrant UQ installed, I was under the truck with the exhaust tech and we found that only the crossover pipe was leaking (black runs of soot) everything else was perfect.

- Aside from roudy exhaust noise from the JBA CBE, the truck is very quiet in the engine bay indicating that there is likely no leaks, especially compared to before.

-The other people posting about this issue also never had any luck with chasing leaks.

Anyways I am frustrated, and my research on here of other people's issues didn't find anyone who successfully resolved this issue.

Can anyone who has triumphed over this issue chime in with the solution?

I do not want to embark on a frustrating journey of constantly wrenching on the truck and throwing money, time and parts at it.

In my state we are about to not need emissions testing anymore. So.....I am thinking of just clearing the CEL every time it shows up.

Really sucks because my truck only has 70K miles on it and ran perfect prior to me futzing with it. I am a former ASE tech and have done lots of mods to my vehicles over the years, this particular truck is giving me issues I would have never anticipated.

 

[seymore4]

Unfortunately most of the people who post those threads don't take the time to report back in with the solution once its fixed, that's why the threads trail off.

It is actually not uncommon for an O2 sensor to fail after header install, they are surprisingly sensitive and the trauma or uninstalling/ reinstalling them can do them in.

A small leak in just the right place could cause this code and not be detectable from the cab. Pressurizing the exhaust and spraying the joints/ O2 sensor bung with soapy water is the best way to check. I remember one guy in particular who argued with me for almost 6 months that he did not have any leaks and everything was perfect only to find out that there was in fact a pinhole leak at the O2 sensor bung. Fixed that and no more code.

Swap the sensors left to right, see if the code changes sides, and you'll know where to look if you want to investigate further

 

[TurboDA6]

I'm still very unhappy with JBA.

These Mexican made headers are not very good quality. My primary ports were all out-of-whack and did not line up with the OEM gaskets. I was assured that this is OK.

The reasons I am really fired up:

-There's no way that the O2 sensor can get ideal measurements from one primary header tube. The sensor used to get 4 exhaust pulses per revolution, now it only gets 1. No wonder the ECU thinks something is wrong. Some trucks may be OK with this, at best, this is a marginal approach that may just work for some, but has aggravated others.

-I decided that I would just buy new O2's and put them down in the collector bungs (I know how to properly extend O2 wiring). With only 100 miles on my truck since the header swap, the hex plugs that are in the JBA collectors are of such piss poor quality that the hex head smeared when I attempted to remove the hex plugs. This is while on my back, under the truck, using my gimpy left arm I just smeared the hex socket.
Which frustrates me so badly because now it seems I need to get REAL creative to drill out the plugs because they are at a terrible angle, if they were just 20-30 deg rotated downward I could use normal tools to drill out the bungs, but now I need to find short drill bits and a right angle drill motor OR OR OR I get to pull the manifolds off.

Maybe there is a micro-leak somewhere, but previously I had MEGA leaks and no CEL. Possibly the upper location of the JBA O2 bung creates super sensitivity to any type of micro leak.....

I should have followed my instinct to install the O2s down in the collectors.

 

[nightowl]

Cajun has sold hundreds of the Stage 1 Packages (headers, bpipes and Uprev Tuning). Very few have issues at all with the primary tube location. When you start cutting wires that are stainless (sensor) and soldering extra length (copper) wire there will be issues with afr readings from the resistance differences and then you have to worry about the solder joint lasting with the stainless sensor wire and the copper strands used for the extra length. Our advise is not to cut any wires or your risking cels and tuning issues. We also always recommend using antiseize on anything screwed into stainless steel or you will have issues removing it. Your best option is to leave the plug in place and have a new $3.00 sensor bung welded in place.

What bpipes are you running with the headers? I didn't see that listed if it was listed sorry for the overlook.


Also I hope you used OEM Nissan gaskets if not that may be your issue right there.

 

[TurboDA6]

First off, let me say, most of my disappointment is directed at JBA. I sent them an email about this.

There is a way to successfully extended O2 sensor wires. You need to use high-temp Tefzel wire and solid-formed crimp splice (not butt splice) solder won't help as it doesn't like O2 sensor wire. The solid-formed crimp is used to crush the two wire together and make an oxygen-free joint. The OEM connectors are the same, take one apart, no solder. Just a good, secure crimp joint to a NORMAL terminal. I had to build 4 of these extenders for an old Maxima I swapped a VQ35 into, in 111k miles I never had an issue and it was running the 2004 I35 OBD2 ECU.

I have Cajun B's.

I used anti-seize, I have anti-seize drips coming out from the hex plug to prove it. SS sucks because SS loves to gall. I agree it may be best to abandon the current bungs, and I would likely have mild steel bungs welded in. I have even heard people have issues exchanging O2 sensors in the SS bungs.
When I installed my exhaust system, some of the hardware was SS nuts and bolts. I threw away the SS nuts and used brass nuts. This helps to prevent the inevitable galling and seizure of SS/SS threads.

All OEM gaskets, as was recommended.

I think the main problem is that having an O2 sensor in a single primary is super-sketchy. While it may work for many people, it CAN cause issues because it is not exactly IDEAL. We went from 4 exhaust pulses to 1 exhaust pulse.

I am VERY lucky in that WA State will no longer require emissions tests after 2020. My truck runs EXCELLENT, is much more powerful than before. My frustration with JBA is that they should not have put the O2 bungs up high in one primary. They should delete that option and ship O2 extenders with their headers for the collector bungs. That way, if troubleshooting is needed, O2 sensor location isn't a concern. Hmmmmm, just why did they include a collector bung??? Hmmmm, I wonder...............

Also, JBA shouldn't be using hex plug. Ugh I wish I would have known, a straight thread (or loose taper) bolt plug with a crush gasket (like an O2 sensor) would have been WAY better!

 

[seymore4]

I think the main problem is that having an O2 sensor in a single primary is super-sketchy. While it may work for many people, it CAN cause issues because it is not exactly IDEAL. We went from 4 exhaust pulses to 1 exhaust pulse.

I have literally done over 1000 tunes with this or a similar set up and have never had an issue because of the O2 sensor being in the upper bung.

I have NEVER had a truck with a CEL that was resolved by moving the O2 sensor from the upper to the lower bung.

 

[TurboDA6]

I have literally done over 1000 tunes with this or a similar set up and have never had an issue because of the O2 sensor being in the upper bung.

I have NEVER had a truck with a CEL that was resolved by moving the O2 sensor from the upper to the lower bung.

When doing e-tune logging, only the upstream O2s are logged.

If there was an issue with those sensors, wouldn't the tuner see it? Especially if it only affected one bank.

Reason I ask, is in Jbowles thread on this exact issue, another member had P2A00 and found that even though the code identifies it as an "upstream" issue, that doesn't mean it is a bad upstream sensor. He resolved his P2A00 by replacing the downstream O2s.

Since the logging doesn't capture downstream, could this be likely? My upstream O2s were textbook easy to remove from the OEM manifolds. My downstreams, however, were rusted in place and required a lot of torch and impact action. (I torched the bung, not the sensor BTW)

 

[seymore4]

If there was an issue with those sensors, wouldn't the tuner see it? Especially if it only affected one bank.

Sometimes but not always. P2A codes can be tricky. I suppose anything is possible but if the downstream sensors were bad 99.5% of the time you would get different codes.

Swap the sensors left to right, see if the code changes sides, and you'll know where to look if you want to investigate further

 

[nightowl]

The problem with 02 extenders is that the nissan connectors are not available, no one can get those things. 5523 Motorsports lost his supplier so we have no options. JBA knows this which is why they offer the primary tube because of the issues people run into by wire cutting. Thorley does not offer a high bung neither did Stillen only JBA and the China JBA knockoffs do. Trust me we have hundreds of guys running the top bung with zero issues.

 

[TurboDA6]

I've been doing troubleshooting on this lately, and all 4 of my sensors are giving good readings according to live data. My truck hasn't set a P2A00 since, not even in pending status. So, I'm going to hold off on the theories until I find the actual issue.

I'm just going to keep e-tuning for now. Hopefully P2A00 is an infrequent visitor

 

[Sangster]

have you tried swapping sides on the o2 sensors, as has been suggested a couple times? If the code follows.....well then you know where to start.

 

[TurboDA6]

No, there's nothing wrong with the O2's per live data.

 

[danman]

the first set of jba long tubes i bought, i sent back. horrible quality. they couldn't even debur the material that was dangling where the o2 sensor was drilled. I made a several minute video pointing out all sorts of cheap labor quality issues, but never posted figuring nobody would really care and there are already videos on youtube about jba quality on other vehicle headers. I did end up with the jba's in the end and found the collector flange on one of the headers is installed slightly off square and slightly rotated, and have always battle leaks unless i fabricated my own b pipes...no premade product would fit without leaking (3 different manufacturers). I feel your pain, and looking to replace the rusting stainless headers in the near future.

Glad you got your issue sorted out tho, seymore4 and jeff have always been very helpful in troubleshooting, not insinuating that you dont know what youre doing, they do want to help when they can...great resources on here still

 

[TurboDA6]

the first set of jba long tubes i bought, i sent back. horrible quality. they couldn't even debur the material that was dangling where the o2 sensor was drilled. I made a several minute video pointing out all sorts of cheap labor quality issues, but never posted figuring nobody would really care and there are already videos on youtube about jba quality on other vehicle headers. I did end up with the jba's in the end and found the collector flange on one of the headers is installed slightly off square and slightly rotated, and have always battle leaks unless i fabricated my own b pipes...no premade product would fit without leaking (3 different manufacturers). I feel your pain, and looking to replace the rusting stainless headers in the near future.

Glad you got your issue sorted out tho, seymore4 and jeff have always been very helpful in troubleshooting, not insinuating that you dont know what youre doing, they do want to help when they can...great resources on here still

The guys I have been dealing with have been great, their hands are tied because JBA is it's own thing. I sent JBA a scathing email over the weekend, and they haven't bothered to reply.

Looking at the workmanship on the JBA headers, and a few other parts issues I had, I am suspicious that the parts on my truck are not of good enough quality to warrant extensive troubleshooting. I went from badly cracked OEM manifolds with no codes, to what should have been a straight-forward install that ended up throwing a code, even though everything seems solid.

I'm lucky, the code isn't persistent and my State is doing away with emissions testing in 2020.

Here's pics that seem to be similar to your experience:






I just don't have faith that the headers are sealing up 100% correctly with the way the ports look..... but I am not going to tear into my truck again to resolve this.

 

[danman]

The guys I have been dealing with have been great, their hands are tied because JBA is it's own thing. I sent JBA a scathing email over the weekend, and they haven't bothered to reply.

Looking at the workmanship on the JBA headers, and a few other parts issues I had, I am suspicious that the parts on my truck are not of good enough quality to warrant extensive troubleshooting. I went from badly cracked OEM manifolds with no codes, to what should have been a straight-forward install that ended up throwing a code, even though everything seems solid.

I'm lucky, the code isn't persistent and my State is doing away with emissions testing in 2020.

Here's pics that seem to be similar to your experience:

View attachment 524743
View attachment 524745
View attachment 524747
View attachment 524749





I just don't have faith that the headers are sealing up 100% correctly with the way the ports look..... but I am not going to tear into my truck again to resolve this.

yea, something like that. I bet your port flange isn't flat either...the first set of jbas i got were not, but probably would have worked. I don't blame you for not wanting to investigate further, the jobs isn't impossible, but also isn't a lot of fun to do. when i get enough cash saved, i'll be investing in new components. again, jeff and joe mean well and want to help when they can

 

[danman]

got to be honest tho...i would not have installed those headers in that condition on my truck. the second set i got were pretty good on visual inspection, only to find alignment and fitment issues once installed. it is what it is tho.

 

[TurboDA6]

got to be honest tho...i would not have installed those headers in that condition on my truck. the second set i got were pretty good on visual inspection, only to find alignment and fitment issues once installed. it is what it is tho.

I asked around, everyone said "that's how they are".

Ughh, I hate looking at those pics!

I used to be in the import tuner scene, DC Sports was the main header to use on Honda's. Never had issues with those!

 

[TurboDA6]

So I have grown tired of paying for 9mpg gas on this truck. This has been an expensive waste of money. JBA doesn't respond to my issue, and there's no other alternative. I'm just gonna source some OEM manifolds and go back to stock. I can now hear my JBAs leaking when in a drive thru, and yes all of the manifold nuts are torqued properly.
I could live with the P2A00, but the piss-poor MPGs are ridiculous.

 

[TurboDA6]

For archival sake, and anyone who may refer to this thread if they experience similar issue, I finally resolved this issue. (NOPE!! WRONG!!)

The P2A00 code applies to driver side manifold. Knowing the gasket alignment issue, and knowing that removing and replacing the manifolds would be a PITA, I figured I could just try re-aligning the manifold. I loosened all manifold nuts at the head, pried the manifold upward and tightened the nuts back down. I suppose that moving the manifold up allowed a better gasket/port alignment. If you look at my pics in post 14, you can see how the ports are misshapen.

It's been a long while now and P2A00 is definitely resolved.

 

['10XE.Cpete]

For archival sake, and anyone who may refer to this thread if they experience similar issue, I finally resolved this issue.

The P2A00 code applies to driver side manifold. Knowing the gasket alignment issue, and knowing that removing and replacing the manifolds would be a PITA, I figured I could just try re-aligning the manifold. I loosened all manifold nuts at the head, pried the manifold upward and tightened the nuts back down. I suppose that moving the manifold up allowed a better gasket/port alignment. If you look at my pics in post 14, you can see how the ports are misshapen.

It's been a long while now and P2A00 is definitely resolved.

TurboDA6,

Has the issue remained solved for you?

I have a similar issue and I've been chasing my tail for almost three months. I have the JBA headers, Cajun B-pipes, and JBA CBE. Approximately 250 miles following install (done at a local, well-respected shop on August 4, 2020) I got the same code -- P2A00. Tried to swap O2 sensors but the threads were f'd up. Had a new bung welded on. Replaced both upstream sensors. I replaced the manifold gaskets and all four b-pipe gaskets (all OEM). Still had leaks, most notably at the header/b-pipe junction -- doubled those up (OEM). Still leaked. Discovered RemFlex gaskets -- NO MORE LEAKS! Now the CEL comes on after 100 miles instead of 250 miles. Changed the Bank 1 downstream sensor and checked for leaks. Found a pinhole leak at the plugged collector bung. Like yours, the plug is not coming out. I hooked the shopvac up, again, but on vacuum this time. Cleaned the plug and bung and then put high-temp thread locker (from McMaster-Carr, rated for 2000*) all around the crown of the plug and sealed it up. Absolutely no leaks now -- period. CEL still comes on at approximately 100 miles.

I do have a twist, tho. Back in March, I had the vehicle serviced at a Dealership. Shortly thereafter, I noticed the idle had changed and it ran a little rough at low RPMs. The CEL light did not come on. I changed the spark plugs, the old looked good but they were getting close to due anyway. Helped, but not quite right. Changed the PCVs, no change. I took the truck to another local shop and had them check it out. They checked for vacuum leaks but came up empty. At the end of the cycle, I changed the oil myself and found that the dealership had filled the oil to 10 - 11 quarts of oil. It idled and ran better after I changed it. Not like it did before, but a lot better. Fast forward to today. It still idles a little rough and at 1200-1300 RPMs it is rough and lacks power. Joe had me run another set of data logs and found that Bank 1 runs lean when just maintaining speed at low RPMs. I hooked the vacuum gage to it and it oscillates wildly at the 1200-1300 range, but is steady otherwise. I took it to the shop and they checked for vacuum leaks again, but found nothing.

The idle/low RPM issue has been around since March, but P2A00 has only been an issue since installing the headers in August. Like you, I was concerned about the quality of the JBA headers. I expected a more consistent port shape and a perfectly flat flange, not raised welds. Holley offers headers in their Flowtech line that have both bung locations. The pictures on their site indicate a completely flat flange with consistently cut ports. I'd hate to throw another $500 -- $600 at this. Who knows, maybe the fourth install will be charmed...

Any suggestions will be appreciated!