Selfadaptation of mixture formation. Mixture is too rich.... W203 - 242...

[wimphot]

Hello all
Having cleared the codes with my iCarsoft Pro, a fair way thru another ghastly stop-start commute journey on a not-too-warm day (outside temp ± 25c) warning light comes back on.
CR Pro says"Selfadaptation of mixture formation, The mixture is too rich in the part load range, [P0172]" which is the same as last time.
The error codes list tells me "System too Rich" which is not as specific as the message from the iCarsoft. (I mention the very slow traffic conditions under which the light came on just in case it has any bearing, possible on the way the cat was working?).
Is this something to worry about? and if so where should I look first. My guess is O2 sensors. Of which i believe there are two either side of the Cat. Can my iCarsoft CR Pro receive the readings from the lambda's when the engine is running, as shown in some youtube vids?
Thanks

 

[Tuercas viejas]

Yes it is something to ,be concerned about.
The condition is dumpling excess fuel into the Cats which causes excess heat across the "bricks" in the Cats which will eventually destroy them with excess heat as it fires off once the Cats "light up" as often mentioned in auto repair circles.
First off don't instantly condemn the O2 sensors, you check them with a scanner to see if they are faulting out.
Going rich at midrange tell me something else is amiss, like an aftermarket, or the air filter being restrictive is the thing plugged up?
Is the MAF unit defective giving an engine fault ,even the gas pedal or the coolant temp switch/sensor.
Here's some useful info to help you before you seek help from a Pro shop like mine.
All the best
Tuercas viejas

https://www.autozone.com/diy/diagnostic-trouble-codes/p0172-p0175-system-too-rich-bank-1-bank-2

 

[wimphot]

Tuercas viejas​

Thank you for responding.
I'll take a look at the items you suggest.