AmbyBomb

No kidding.

Sasnuke

The code should only trigger when you're decelerating as the timing of it is related to fuel cut...which most commonly occurs on decel.

Joe Z

iTrader: (10)

Once the CEL event occurs it’s ON until cleared…

At that point acceleration or deceleration doesn’t matter any more..

I saw your long post, but here is the response best explaining why a leak tiggers the O2 deficiency as well.

“Past the O2 sensors and catalytic converter, it is very unusual for the exhaust leak to cause a code.

Before the O2 sensors, a leak will throw a code.

Understanding low throttle, the leak will allow fresh air to enter the exhaust. The O2 reading shows a lean mixture, so the engine computer enrichens the mixture. That can cause various problems, including misfire warnings (rich mixtures are harder to ignite) and engine too lean (it is measuring the fresh air and cannot ever sense a good mixture).

Exhaust manifold / flange leaks have the effect of “fooling” the oxygen sensor. Exhaust gas travels in pulses with high and low pressure zones. Exhaust gas leaks out during the high pressure event. Outside air is drawn INTO the leaking area during the low pressure event. The result is an oxygen sensor that reports a lean condition. (Too much air in relation to fuel). The ECU will then increase fuel delivery to compensate. With a leak of sufficient magnitude, the ECU can end up substantially increasing fuel delivery in an attempt to “correct” the perceived lean condition. The engine (or that half of the engine) actually ends up running quite over- rich (Too much fuel in relation to air).”


Exhibit A


To sum that up, if there is leak occurring at Exhibit A, because of a bad flange alignment or bad gasket.. It will throw the CEL code for O2 deficiency.. Fooling the sensors..
Or if the sensor(s) are bad / defective, it can’t read correctly, it will throw the code..

Unless there is something else wrong maybe the upstream CAT(s) on the manifold, or as I mentioned a software issue..

Once they lock down the root cause of all these cars having CEL and their codes, I do expect the LSB to be issued.

Would I call this event a reason to label this car unreliable?? Absolutely NOT…

No car manufacturer is perfect.. Including Lexus. I trust they will get over this hurdle!!

As more owners experience this, my suggestion is ask for the codes your car has triggered.

Sample:

DTC code P013A Bank 1 Sensor 2 - Which is a leak in the left side OR potential for a bad O2 sensor.



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Joe Z

cbroccoli

This is my first Lexus so I don’t have any experience to go off of. Do you think they will get this figured out?

is500le

NO, best to sell now.

wthrman2

cbroccoli - Absolutely, I have no doubt they will figure it out and they are likely troubleshooting it as we speak. It may take a little bit of time but given the number of failures that have been reported (with respect to the percentage of unit sold), they will try and solve this ASAP. They don't want a bad reputation in general, especially less on a new trim (F Sport Performance) because this car is launching the trim, and they don't wanna have bad publicity associated with it. If the Type S from Acura was affected by a whole whack of issues when the TLX came out, they would have jumped on it too

Moonman89

At least we don't have the Cylinder 4 ringland failures like Subarus lol

AmbyBomb

It seems like Lexus is working hard to fix the problem, and I'd much rather have a short-term problem related to a defective, replaceable part than a problem related to a poor engineering decision.

Sasnuke

Hey @Joe Z ...rather than quote your entire post, I just quoted the code.
Let me say first that I agree with everything you said.

For the two O2 sensors in the vehicle there is a possible 10 codes...of the 10 possible codes, 7 have exhaust leak as a possible cause.
My concern is the particular code that is being thrown, P013A (I assume every IS500 has this code), and that there is no parameter given to the severity of the exhaust.
For a very small leak from a flange gasket in front of an O2 sensor I would not expect P013A.
If you drilled a golf ball size hole in the pipe in front the sensor, then yes, I can see a P013A occurring.
Considering no one has mentioned hearing an exhaust leak, I'm very skeptical that the gasket will fix it.
As we've seen already the gasket did not fix it...so I'm not surprised at all.
If the part number for the Bank 1 and Bank 2 O2 sensors are the same, then my thought would be the O2 sensor circuit, or a software issue.
The theory is if the sensors are the same, and the sensor is the issue, then you should get the code on both Banks.
Since the gasket does not seem to fix the issue, then we're down to the specific circuit (wires, connectors, etc.) or a software issue.

arentz07

I don't think this would stop me from buying the car. Clearly this is an established drivetrain and should easily be fixable. It'll just be down to Lexus doing a recall and correcting their production going forward (i.e. revising parts or processes to avoid the issue).

Joe Z

iTrader: (10)

This code is an exact code found when RC F owners install a full exhaust system and it’s not done right.
Or a leak developed over time at the flange to manifolds..

O2 Sensor - P013A code


We have a similar known code on the IS F when P0420 / P0430 appears..

So far we know one not fixed yet… While we know one that was easily..

Not sure what other owners codes or experiences are at this point.


Joe Z

Sasnuke

I stand corrected them.
I skimmed the thread you linked and didn't notice anyone mention actually hearing an exhaust leak...which seems to be on par with the IS500 issue.
That one pic where the guy lathered the flange in gasket sealer, not gonna lie, I laughed hard lol!! That was priceless.

For the one that was easily fixed (I'm not sure which member that was), it would be nice if we could get periodic updates.
It's fixed now, but is it really fixed, or the issue is just not occurring at the moment? Cause the same fix didn't fix the other vehicle.
So is there really still only one problem that isn't resolved, or do we have two problems causing the same code?
Questions that we may not know the answer to for a while.

wthrman2

^^ That user was macmaster and he said that so far, it is still fine but as you said, will it last?

PS...It is great to see this thread come alive and people posting very relevant info

macmaster

that was me and it’s been 950 miles since I got the the code fixed. I haven’t had an issue since.

Sasnuke

@macmaster Just to confirm:
1. You had code P013A
2. You had no audible exhaust leak
3. Replacing the gasket at the flange in front the O2 sensor corrected the issue to date