Just scanned my car because of a CE light on the last four days. Registered with a P0172 System too Rich (Bank 1) DTC. It registered as both a TROUBLE CODE and as FREEZE FRAME code.
We've been experiencing frigid temps for three weeks here in Seattle (34F or lower) and that's when the CE light started. It's worth noting this is very unseasonably cold.
Some questions for those of you with experience:
-- is a "System too rich" condition typically indicative of a faulty O2 sensor (an instrumentation failure) or condition that cascades from a fault in another sensor or component (perhaps fuel injection system)?
-- if it is a true rich mixture condition, is it something that might be caused by the type of gas I use?
-- do low temps or extreme temp differentials typically accelerate the failure of an already failing O2 sensor?
-- should I wait for 40 warm up cycles to pass to see if the DTC clears?
-- if it doesn't clear and I let the condition go, what are the ramifications of a continuous rich fuel mixture (if indeed it is a true condition and not an instrumentation problem aka false error condition)?
I'm not too cheap to buy a replacement O2 sensor (a $90 cost) -- is it a DIY job for someone technically inclined? Thanks for any thoughts and speculation.
Mike Seattle