What are the symptoms of a failing catalytic converter?

Feb 8, 2023 ... If the spark plugs have a matte black or grey appearance, it could be carbon fouling — something typically caused by a fuel mixture that is too ... Aug 18, 2001 ... Rich mixture and or rich main jets can cause the carbon/plug problem but if its really bad enough to cause a problem you should see black smoke. Apr 13, 2023 ... The unburnt carbon will be deposited on the spark plug, causing carbon build-up. ... Every car has an oxygen sensor, which monitors the air and ... Carbon-fouled. Ash-fouling. Ferrocene. Oil-fouled. Partially melted center ... Cause: Spark-plug replacement interval not complied with. Effect: Misfiring ... ... spark plugs when you accelerate the next time (with OIL). A fouled, or carbon-fouled SPARK PLUG will NEVER cause a fault or warning horn. Secondary ignition ... Jun 5, 2016 ... I've heard that black carbon on the spark plugs is normally caused by a rich fuel mixture. This can cause the mixture to wash down the cyl. Apr 8, 2013 ... The resistors are there to supress radio frequency interference, which can cause the TCI to malfunction (weak spark, mis-timed spark), or even ... Jun 1, 2001 ... SO, if your distro went spazmo, it could very likely have caused some plugs to foul (weak spark can do that). ... plug has become carbon fouled, ... Sep 8, 2020 ... A YouTube guru on the Nissan VG33 said this plug is more prone to fouling because the oil pools up more in this part of the head due to a flawed ... Mar 31, 2010 ... It is possible to foul a spark plug when running it at the proper temp. range, but it isn't very common. One good example would be oil fouling.