As I was driving last week, the check engine warning, emission warning and parking break system warning lights all went off at the same time. there was no previous warnings and the car drove just fine. I tested the parking break and it worked, so I turned off/on the car several times and let it sit overnight but the warnings didn't go away. I finally made a trip to the dealer, they verified the lights were on and kept it for a few days.

when I got it back, I asked what it was and they simply didn't know. they just cleared the codes. it was error code P2097 "System too rich B1". I was surprised that the dealer couldn't figure it out and just clear the code without any investigations (I could've done that myself). does anyone know what this code means? is it typicall for the dealer to just clear the code without doing any work?

 

yes, that's how you trouble shoot.

if the code comes back, real problem.
if code doesnt come back, fluke...

so, p2097 has to deal with emissions. it's saying that one of the 02 sensors is reporting back a rich condition. it could be a fluke, or it could be a real issue...we dont know, so they reset the check engine light to see if it comes back up.

if the ECU detects a rich condition again, it will throw the light with the same exact code, and the dealers or mechanics or you can choose an appropriate course of action

 

^clearing the CEL is way better than throwing parts at it, because throwing parts without knowing whats wrong is a waste of time and money.

 

Pet peeve

Attachment 101323

 

oh give me a brake..

 

Thanks for the quick response, Justnspace! I am always worried about these type of errors since my car is a first year TLX and I am sure there's still kinks with the ECU they haven't ironed out yet.

 

^fyi, I modified my 2006 TL to where I have no cats. I trick the 02 sensors by sitting them a little above the oxygen/fuel stream.
SOMETIMES, sometimes, I do get an emissions error, while driving telling me that the car is running rich.
if I keep driving, it usually goes away.

since your car is pretty new, hopefully the 02 sensors just caught a bad reading, a fluke, and then resumed seeing normal oxygen/fuel ratios

 

This may seem far-fetched to a lot of people, but as a geophysicist I often run into situations with sensors and electronics that generate a voltage (like oxygen sensors do) where the computer gets an incorrect voltage reading due to impressed or secondary electromagnetic (EM) fields. For example, having a voltage generating instrument (piezoelectric trigger in my case) near a high-voltage power line that is generating a strong EM field can cause a voltage in the wire connected to the sensor that was *NOT* generated by the sensor! As a result the computer is receiving a voltage but the sensor didn't generate that voltage. There is no way for the computer to know the difference if the voltage is close in magnitude to the one generated by the sensor.

I'm not saying this is necessarily what happened, but it's often the cause of a lot of 'one-off' or 'fluke' situations. Sensors do not generate a voltage for no physical reason - there is always something.

 

I just had the same sensors come on in my 15TLX. Bringing it to my Honda/Acura guy on Monday. I hope they just have to reset it I would be happy about that... Might just buy an old TL or TSX as those things never have problems. My parents just gave me their 04 TSX, 160k and not a single thing just oil, brakes and tires. That's how it should be.