my stft1 is reading -2.3 when evap is purging and after the purge has finished 0 on 2007 Volvo C70

my stft1 is reading -2.3 when evap is purging and remains between 0 and -2.3 after purge has completed! could this be a factor in why re-fuelling my car is a chore? takes about 10 minutes for half tank. kind regards graham

by in Tacoma, WA on March 07, 2014
1 answer
ANSWER by on March 07, 2014
While it's in purge mode it is drawing on the fuel system, and that is why it shows rich.