Could exhaust leak trigger Code P0136?
 

Hi all,
For a while, I had an exhaust leak on my 01 RX. It has gotten progressively louder since maybe the last two years, I thought maybe I would be able to ignore it.
But tonight, I was driving home, and the front left tire suddenly hit a sharp bump (from poor construction work on the road). Only 2 seconds later, both CEL and VSC lights come on! So when I plugged in my OBD BT reader and open Torque app, it only showed one code: P0136, described "O2 Sensor Circuit Malfunction, B1 S2."
So what I am interested to know is, is it possible the hard jolt from the bump loosen the broken exhaust leak enough that this code would be triggered? When the status of Emissions Controls is checked, everything shows as "Ready".
https://cimg3.ibsrv.net/gimg/www.clu...df396a7fb4.png
https://cimg4.ibsrv.net/gimg/www.clu...1316a6673e.png
If someone could weigh in, I would be appreciative.

Its possible if the exhaust leak (before the cat) is significant to change the voltage read by the ECU from the O2 sensor.

Voltage output of heated oxygen sensor (bank 1 sensor 2) remains at 0.4 V or more or 0.6 V or less when vehicle is driven at 31 mph or more after engine is warmed up (2 trip detection logic)

I actually have been driving with an exhaust leak at the flex pipe.
Never had the 136 code but when i did, I ended up replacing the O2 sensor and that fixed the 136.
I eventually fixed my exhaust leak.

Update: The CEL and VSC lights did not come on while driving around today.. However, the Code P0136 is still stored in the OBD memory when checked on Torque tonight.
I plan to go get the exhaust repairs done sometime this week and clear OBD. Hopefully that will take care of it.

Please make sure you are not reading a 'pending' code. Pending could be due to past error, if not cleared, or new accumulation which has not happened enough times to pop up as real error or cleared out.

Salim

Salim, you are correct, the code status did in fact change from Active to Pending, when I checked after CEL stays off.
But anyways...

I did go to the local Muffler shop yesterday, they found a break (I mean, you could put your ear close and hear it) between the cat and the flex pipe, also the flex pipe itself was very worn and needed replacement. So I got both of those fixed, the vehicle is now quieter compared to before. In fact, it even seems there is a little more power to the engine compared to before, especially on acceleration :dance:
OBD was reset by Torque, will be running later the Readiness Drive Patterns (I saved the PDF) to get the O2 and Evap monitors set, and hopefully it will be ok.

Thanks.

Question: Since making the mentioned exhaust repairs and resetting ECU, I am still in the process of performing the Readiness Drive Patterns. If I am successful in completing the O2 Pattern without triggering CEL and no Code is stored, am I in the clear with regard to this specific original condition?
https://cimg5.ibsrv.net/gimg/www.clu...26b9dc2041.png
https://cimg7.ibsrv.net/gimg/www.clu...57327fac53.png
As far as Evap System is concerned, according to the guide the outdoors temperature should be between 40 and 90 ℉. Here in Chicago for the last week it was no warmer than 10 - 15, today it was 32 in the morning.. I tried that pattern this morning, but it did not get set :sad: so I may need to wait a while until it gets warmer a bit .

You are good to go my friend.
You are right that Evap readiness will never run with frigid temps.
(wait till Wed.) Lol
But if you need an emission test, only 3 monitors need to run for you to pass.

Awesome. Guess all we have to do for now is brace for Wednesday high. -12 ℉! :cool:
I'm just curious, what is your source for what you say that "only 3 monitors" are required for the Emissions test. Because I did take a look at Illinois Air Team website, it saying that for a vehicle of this age (2001+) there can only be maximum 1 non-ready monitor to pass.

"Remember, vehicles are rejected when more than two (2) non-continuous readiness monitors are “not ready” for 1996 to 2000 model year vehicles, or when more than one (1) non-continuous readiness monitor is “not ready” for 2001 and newer model year vehicles."
https://illinoisairteam.net/vehicle-...diness_monitor

Of course, not that I care too much about that right now. My license plate doesn't expire until end of October :rockon: by which point the test would need to be taken care of.

Here in Texas the Emission test results need to be within 3 months of annual or new registration. For October activity, the earliest one could do would be July.

Salim

Our Emissions Test in Illinois is somewhat similar... You can attempt a Test anytime within 4 months that the plates expire, but the renewal can only purchased within 3 months (of current one expiration). Test is conducted every second year based on your vehicle year (even year model test in even year, odd year model in odd years), and exempts certain types of vehicles (all-electric, light-duty diesel, purchased new within last 4 years, etc.) and vehicle owners who do not have an address of registration in the two largest Metropolitan areas of the state (Chicago and East Saint Louis).

Funny, I live in Chicago, Emissions testing is generally required every alternate year. However, my warm weather ride, 2013 Honda CB500x Motorcycle, operates with EFI and has CEL. Because motorcycles are also exempt from the test even if registered in a required area, I could ride around with the CEL on (if I was desparate enough) and still get my renewal sticker every year! :p

Update:
https://cimg9.ibsrv.net/gimg/www.clu...ee17e17131.png
It's warm today :D

Hahaha..!?
Nice.
Now go get your emissions passed.

https://cimg3.ibsrv.net/gimg/www.clu...f911e924d5.jpg
https://cimg5.ibsrv.net/gimg/www.clu...9cf3a469a5.png
Ouch, same trouble again .. popped up last night. What to do :egads: