beasted

Recently had my r3 2009 rebuilt, street ported with d585 coils + dwell time map and decat sensor eliminated in the ecu so once decat is fitted it won't pop on.

I still have the original cat on the car from when the apex seal went and after the rebuild.

Driving back from the rebuild I got to 100 miles pulled into services to use the toilet, got back in and after pulling back onto the motorway the light popped on.

Checked once home after a further 90miles and code was P0137 was there, I cleared the code and drove for about 10miles hasn't popped bk yet..!

Any help on this would be great as if my cat has gone I will put my toyo decat on asap!!!

As far as I can tell that code is a low voltage O2 sensor or something but please correct if I'm wrong.

Also what I should do from here on like change sensor or cat' ect.

Thanks

Luke

poacherinthezoo

Sounds like the method of blocking the ECU from detecting improper post-cat O2 sensor readings may have either (i) only been applied to the P0420 code or (ii) didn't fully "block" the ECU from receiving the O2 sensor codes.

Let me get this straight, you are currently running with a cat, and getting this code? Your engine was lost due to hydrolocking/water breaking the apex seals if I recall correctly. I'm not sure, but a big dose of water out the exhaust port may have been enough to damage the cat or the O2 sensor.


I'm currently cat-less and I occasionally get the P0137 to pop up. When I clear it, it goes away for another 4-6 weeks. The P0420 is the one I see on a regular basis.

badinfluence

Sorry for a thread revival but I am having the same issue, with a bone stock R3 with a cat. 41k. Doesn't appear to be the coils or plugs. I replaced the B1S2 o2 sensor and it is still running rich as ***** with 10.2% LTFT. (0 STFT), with some ECU/PCM hiccups. This was one of the only threads I found for P0137.

Could it be PCM related? Googles sayz that it remained "low" for 2 minutes is the code, but does P0137 mean "open"(null) or "low" (0)? If it is open, then I think I have a grounding problem, if it is low, then that is a different problem entirely.

wcs

iTrader: (2)

Well I can't find P0137 in this list
https://www.rx8club.com/series-i-tec...n-guide-26291/

I don't believe codes that I can't find in this list ... that said I do recall seeing maybe 1 or 2 time before that legit codes are posted that are not listed in that thread.
So that said, on with it.

edit: LOL Just noticed this thread is in the SII section. The following codes are posted in the SI section however I believe they do still apply

First I'm not familiar with the term B1S2 -- Bank 1 Sensor 2 I'm guessing in the Rear O2 sensor.
Here are the codes I'm familiar with:

P0130 - Front HO2S circuit problem
P0131 - Front HO2S circuit low voltage
P0132 - Front HO2S circuit high voltage
P0133 - Front HO2S circuit slow response
P0138 - Rear HO2S circuit high voltage
P0139 - Rear HO2S circuit slow response

Just a guess but a P0137 is likely something to do with the rear O2. But if not you may need to buy a new Front O2 sensor.
Did you buy an OEM replacement or aftermarket?

Do you have any modifications? Like an aftermarket Catalytic? (midpipe)
Have you checked for vac leaks?
How do you know it doesn't "appear" to be coil or plugs?

You should provide a RPM and G/S if you can with the LTFT it changes at different set points. The fact that you said it has 0% STFT makes me suspect you were in open loop. If in fact it is +10.2% LTFT (as oppose to negative) that means the computer is adding fuel because it believes the mixture to be lean.

You say it smells rich ... well that is a good indicator that the catalytic has gone bye-bye

Clean MAF, ESS, do reset dance
Test coils with HEI Coil tester
Check catalytic that isn't clogged or completely gone.

Let us know what you find

badinfluence

Bank 1 Sensor 2 for B1S2
OBD-II Trouble Code: P0137 Oxygen O2 Sensor Low Voltage (Bank1, Sensor2)
It is a pretty universal code. At first the dealer said the CAT was prob bad, but they changed the o2 sensor and the code cleared..... for now.

No Vac leaks, had the dealer check, and they aren't a normal idiot dealer. Most of them have FCs. (Not sure why they all have S4s, but more power to them!)
Bone Stock
It is usually 0% STFT and doesn't make small corrections often which is just weird, even if they are small like 1%.
Coils have no short spots, Rev B.
Dealer installed OEM O2 Sensor.

The dealer thinks it is fixed, but damn is it running rich for a stock car. (Smelling) I see it "thinks" it is 14.7 most of the time after it is warmed up, but I seem to never see 15.0 like most cars. Prob wont' with that +10%on the best of days it hangs around +7.8

Ill pull a log. I have logs from Feb 2014 onward.

I hope it is the CAT, I would get a free replacement, and maybe they let me keep the old pipe for a crunch dump gut, and just be done with the damn CAT pipe.


The weird hiccup problem happened before the o2 sensor started going off. It is like a 1 second drop in power with a full out resume. Not like a linear drop or fuel cut, but like a delay, then it's fine.


The car needs some TLC before summer, so I am hoping very soon I can give it a shakedown again. I usually try and pull the intake clean the piping, change the Air filter, clean the grounds, check everything after I remove the battery. This time I plan on adding lock washers to dig in more, and to change the whole ignition system. Prob just go with Stock Rev C coils and insulate the bottoms with some rubber padding to avoid the dealer rain dance.

wcs

iTrader: (2)

Thanks for the link.
So by that definition it's your Rear O2 sensor which is only measuring the efficiency of the Catalytic Convertor.
(Just so we are on the same page there is a Front O2 sensor which in fact is a Wideband O2 sensor)
It could take a several drive cycles for the check engine light to go off again.

As a side note there has been discussion on the forum whether or not the narrow band sensor actually provides any input to the fuel trims (at least for the Series I).

About the STFT value. Agree these values should dance around a bit, especially during moderate throttle changes.

About the spots on the bottom of the coils, don't pay any attention those spots.
There is a TSB about those spots
Link: https://www.rx8club.com/series-i-tro...letins-183774/

(Go to post #6)

It's more or less been proven the only way to test the coils is with an HEI Coil tester
https://www.rx8club.com/series-i-do-...-wires-222641/

About seeing AFR's at 14.7 and not 15 ... I assuming you mean at idle not under load. At idle my car sits perfectly at 14.7 and most that I've seen do as well. This doesn't seem unusual to me, so no problem there.

Again seeing the LTFT values at +7~10% at idle isn't ideal but really isn't that bad but could mean a small vacuum leak, where unmetered air could be getting in to the system.

About the weird hiccup, do you know what RPM that is happening at?
Does it happen only under heavy load or WOT?

If you could post some logs would be great, especially if you have one with the drop in power.

Strong smelling exhaust on a rotary almost always means the catalytic is shot.
If you think your exhaust stinks now wait until you try something without a catalytic. It's honestly enough to make your eyes water.
My wife wont even get in the car ... (I kind of like this feature)

If I was you, I would inspect the catalytic.
Remember there are 2 elements in there, you'll only be able to see the front one.
Look for cracks, melting, chunks missing, give it a shakes see if you can hear rattling.

Good luck, keep us posted please.

badinfluence

The power loss appears to be random.... It hasn't done it in the last 5 days despite my best effort to get it to do so.

I saw my Speed go between 14.7 and 15.1 so I wasn't sure if the RX8 targeted a bit leaner at idle to compensate for the hot start problems.

Sadly the ECU disconnects during the hiccup or logs the last bit of data in the cells till reconnect. (Like stuck in state 3, vs High or Low)

Pretty sure the cat is shot. I am going to see if I can get it replaced, if not it gets smashed out. Maybe add a spark plug like the 50s cars? lol.......


Here is what I think is going on.....

I think the O2 sensor was slowing down a module and dipping the CANbus randomly, and since it is replaced it seems to not do so anymore. Another thing I think didn't help is that I had my ODBLINK MX at enhanced fuel caluations, and I could have been doing the extra 50% damage to the CANBUS to slow it down.

I think my PCM or TCM (Not sure which does the traction or if I have a TCM), is a bit flaky since the traction control like occasionally comes on with U1900 (always grey, never red and goes away every drive cycle)

I think replacing that narrowband did the trick, but I am going to inspect my grounds just in case and beef a few of them up. I plan on relocating the battery so this is all just prerequisites.

Could be one or more, but it seems if it is just one, the car won't reproduce the issue. Whatever, it is a rotary and a pain in the ***, but when they rev up, its all worth it somehow.

wcs

iTrader: (2)

Ok sounds like you're making progress.
Thanks for the update.

I'm guessing you meant your AFR was between 14.7 and 15.1 -- I am not aware of any modifications to ECU software to compensate for hot start problems, but maybe. <shrug>

Keep us posted.

badinfluence

By Speed I meant Mazdaspeed3. Sorry about that.

Yesterday it threw P0155, P0100, P1900, and P0121. So the CANBUS wiring or PCM is going in a big way. It escalated very quickly!

Back to the dealer, glad I didn't touch the wiring yet.

badinfluence

More codes than that! 30 CANBUS codes stored after driving <150 miles!

First it was somehow the narrowband, but now....
So I got a call yesterday that it was the Steering Angle sensor, and it was not covered under 3rd part warranty. I know some things about CANBUS and I am calling Bullshit on a sensor derailing the entire CANBUS system.

The car was misfiring, running RICH AS *****! (Drove 15 miles used 1/4 tank!), and only throwing CANBUS codes stating the PCM was bad. No a single misfiring code. Kind of disappointed in my dealer right now, but I have a friend there so I can't kick and scream because I don't want to lose a friend over it. I authorized the sensor, but I am almost 100% sure it is the PCM.

I pointed out that everything connects to the PCM, and that I predict a new sensor will somehow say it is bad after replacing the Steering Wheel Sensor. (BTW Steering Wheel sensor is 1 CEL, not 29)

I took a look at the CANBUS raw data and there was "****" going on instead of your nicely flowing strings and addresses. I compared it to my Girlfriend's 2, and it was a joke compared to how smooth the 2 was. Every other line there was errors on the RX8.

So it does other weird **** too, like the door courtesy lights have never worked despite the fuse being fine, and both bulbs working if you apply 12v power. Harness for all of the car is intact as far as I can tell and it has some other weird behavior pointing to something on the HS-CAN being fucked up. (Or the Instrument panel of course since it is both worlds)

I just can't see a sensor that is more than likely a variable resistor killing a CANBUS considering CANBUS is supposed to be amazingly failsafe.

This is why I have waited to mod anything. The never mod a questionable setup here may have saved me about 7k. (PCM, maybe other things on the CANBUS, and if I had modded it I would more than likely have blown the engine)

Anybuddy got some ideas on how they are connected? I read the FSM and don't really get how they are getting what they are getting from the codes I saw, the CANBUS freak out, and the fact that one sensor has been replaced already.


EDIT: I Take back part of what I said. Got the "bad" sensor back today, and it passes can through like a slip ring (Wire joint that rotates) It has 7 pins on it, so it could interfere. Was was fine till I turned on the A/C and Marker lights then it went rough and Poof CEL.