Sooo 2005 cavalier auto. Bolt ons. Stock tune atm. No vacuum leaks. And have an aem wideband and its saying im running super rich at idle and driving wot or regular driving. So going through gas like a v8. Also has a slightly higher idle instead of 550 its more around 1000 rpms. Has big 3 so all grounds are good and updated. Checked and no slack in chain and has updated tensioner. No noticable vacuum leaks and have a vacuum gauge hooked up anyways. Did tune up, new delphi oem injectors, new idle air control valve, cleaned throttle body, checked for binding in throttle cable, swapped coil system from my 04 lss and no change so swapped original back in, so im pretty stumped atm as to whatsup.

Forgot to mention also replaced fuel pressure regulator.

Have you done any modifications to your intake system? Like adding a chip or resistor to the IAT sensor? The Intake Air Temperature (IAT) sensor controls the air-fuel mixture provided to the engine by reading the air temperature coming into the intake. In cold weather it can act like a chock by richening the fuel mixture and raising the RPMs of your engine until the engine reaches operating temperature . It sounds like your engine is operating in a state of constant choke to me. If you have modified the sensor, or relocated it to get a cool air intake effect of increasing engine performance, try reversing what you may have done or replace the IAT sensor and see if that works.

thanks james but it just has an ac delco ait sensor and it is in the correct location has been like that for years and no codes for iat either. have a mystery code for cam position sensor but have since replaced all 02 sensors and ignition module and coils and plugs. along with everything else mentioned. no onvious fraying or broken wires in connectors either. but had that code before it ran rich. starts fine runs decent other than high idle and poor mpg and af gauge reading pig rich. 10.4 area