Quote:
Originally Posted by neanderthal  but arent unburned hydrocarbons the result of poor ignition, rather than fuel? |
Overly rich condition is not caused by ignition....
Either case, poor tune or too rich can cause the unburned portion to ignite in the cat, potentially causing damage.
How do I know?
We rattled the bricks loose on two brand new 5.0L Merc cats on the dyno, while setting the fuel maps for the twin turbos.
Perfect ignition, just a bit too rich for the stock cat.
Didn't have a problem after we installed a newer technology spun metal cat.....