Q: I have a 2009 Pontiac G3 with a 1.6-liter engine. The “check engine” light came on about six months ago showing a P0420 catalytic converter efficiency code. Since then I have replaced both oxygen ...

Thanks to modern fuel injection, the engine computer has extremely precise control over the proportions of the air/fuel mixture inside the cylinders. A countless number of sensors around the car tell ...

Q: I have a 2010 Honda CR-V. Last month its check engine light came on. I'm a retired mechanic and my scanner found code P0420 — catalytic converter efficiency. I tried a catalytic converter cleaner.

My 2005 Nissan Altima's "Service Engine Soon" light has turned on twice in the past month. A diagnostic test indicates that my catalytic converter is "failing". If I don't have the converter replaced ...

Question:I have a 2001 Nissan Pathfinder with the 3.5-liter V-6. The check-engine light came on, and I had code P0420. I was told it was a bad catalytic converter, so I went ahead and replaced it ...

Question:I have a 1996 Chevy C1500 pickup with a 5.7-liter. I recently had to replace the old CSFI unit with the upgraded MFI due to a misfiring problem that wouldn't go away. After the upgrade, it ...