2004 Mazda 6
Vehicle sits and rocks when idling at less that 1000 rpms. Will stop if AC is turned on. Could the problem be the oxygen sensor in the exhaust system or possibly something else. Auto Zone says too much oxygen mixing with fuel. They are thinking fuel injectors. Any ideas?
It could also be a bad intake gasket or other air leak in the intake, such as loose connections or a hole in the intake tube. This would cause too much air to enter the engine giving it a high idle with too much oxygen. (lean)
I suspect that the IAT sensor...the digital equivalent of your choke is buggered up...unfortunately cannot get a picture or availability...no one seems to have one, but I know it's there (because your computer needs to know ambient temperature to enrich when cold) as well as the engine temp sensor should be looked at and possibly changed for the correct air/fuel mix...always use Silicone replacement vacuum hoses to get rid of those 2 degrees from chewing gum with a little coal tar in that type that crack and leak and will stop devices from operating properly like the egr valve and the fuel pressure regulator~
Been reading where several other mazda 6 owners having similar issues. Some stated that a busted/cracked pcv vacuum line/connection was their issue. Check for vacuum leaks. Also one stated that along with the vacuum leak he had bad motor mounts. This caused the motor to rock/jerk around at an idle while it was not running right. Now a bad motor mount will not cause the motor not to run right but could cause the rocking you are talking about. Hope this helps.
