2003 Forester smells strongly of fuel at times; I have checked for leaks and tightened all clamps, to no avail.  I also changed front O2 sensor to try and improve mileage (18 mpg), but I still get an occasional P0420. Could this be an injector leaking internally causing rich running, or would a rear O2 help? Thanks.

stronger out the tailpipe, underhood, in the cabin? -  after fueling or ????

 

sometimes filler tubes can have holes in them under the plastic cover.

It happens sporadically, smells thru vents but exhaust smells rich also.  Does this car have a MAF sensor or just a MAP, could have have an effect?

is the CEL coming back on quickly after a reset? any other codes? You may need to retrieve live data.

if it seems worse on a cold morning, you may still need to look for a fuel clamp/connection to tighten.  Some folks have had injector seals leak a little.

 

doesn't take much gas to really smell.

Edited February 18, 20197 yr by 1 Lucky Texan