sudden decrease gas mileage
6 Answers
PS...this is my 9th volvo...I am not new to the wonderful world of volvos. Each one of my girls have s70's and my husband and I have xc90's! Any advice? Fuel filter??
What is your mileage? Is the temperature guage reading the same? Is there Black soot in the tailpipe? Has the idle speed changed? Is the check engine light on?
Sorry took so long...wanted to have car checked out. 7 codes came up. But milage is 147,000 K. There is black soot out of tailpipe. Rough idling not stalling, but uneven idling. Check engine light is on. Thank you!
ps..no the temp. gauge wasn't reading right and had thermostat replaced too. Thank you so mucha again!
My guess not knowing the codes with soot, low engine temperature is the front O2 sensor. Have the codes checked ( free at Auto Zone)