I am taking my '03 Toyota Echo to a garage tomorrow to check if its O2 sensors are still good because the gas mileage has dropped by 10%. I was dumb enough to put ATF in the gas tank twice hoping to remove carbon deposit in the engine few years back. I was told that ATF will foul up the O2 sensors. That is the reason for the visit.
When I made an appoint with the garage, I was told that the O2 sensors should be checked with the exhaust pipe being cold. I vaguly remember from this forum that they sould be checked at the operating temp. Could someone shed some light on this?
When I made an appoint with the garage, I was told that the O2 sensors should be checked with the exhaust pipe being cold. I vaguly remember from this forum that they sould be checked at the operating temp. Could someone shed some light on this?