Alec of the Know-how Connections YouTube channel acquired a test engine gentle and the dreaded P0420 code on his Nissan Dice. He is finest recognized for his deep dives into how family home equipment and hopelessly outdated electronics work, although he has often ranted about automotive topics like brake lights and flip indicators. Now, he is turned his consideration to the catalytic converter, that costly factor below your automobile that will get stolen on a regular basis and helps with emissions, to determine why his Dice has this code. After watching this, I perceive how catalytic converters work higher than ever.
He begins by explaining what’s inside a catalytic converter. We have lined this earlier than;, however as a fast refresher it is a ceramic honeycomb construction coated with platinum, rhodium, and palladium, treasured metals which can be the rationale cats get stolen so typically. These metals act as a catalyst that, notably when mixed with excessive exhaust temperatures, convert unburnt gasoline and dangerous nitrogen oxides that produce smog and acid rain into nitrogen, carbon dioxide, and water vapor, which is why your tailpipe typically drips water. This chemical response takes place robotically, however the engine laptop has to do loads of work behind the scenes to make it work successfully, effectively, and final greater than 100,000 miles usually.
It is all laptop
Because of fashionable gasoline injection, the engine laptop has extraordinarily exact management over the proportions of the air/gasoline combination contained in the cylinders. A numerous variety of sensors across the automobile inform the pc how nicely it is doing, however the ones we’re involved with listed here are the oxygen sensors earlier than and after the catalytic converter (or converters, as some engines, notably V6s and V8s, have two, one on all sides). By evaluating how a lot oxygen goes into the cat and the way a lot comes out, which must be near none, the pc can alter the combination to optimize effectivity within the cat, in addition to the engine itself. When the pc’s finest efforts cannot dial the oxygen out of the again aspect of the cat, it triggers the P0420 code.
There’s a complete lot extra on this video, together with learn how to inform if the issue is a nasty sensor, an exhaust leak, or that the catalytic converter itself has failed. Whereas Alec makes use of a professional-grade OBD2 scanner to diagnose that he did, the truth is, have a nasty cat, a shopper scanner will allow you to do the identical factor. After watching this, I would like my spouse to take me for a drive in her 4Runner so I can monitor the oxygen sensor information and diagnose her P0420 code. I hope her cat is not cooked, nevertheless it could be, as a result of it failed after some misfires occurred. I changed all of the previous coils to repair that downside, however unburnt gasoline throughout the misfires might need fouled the cat, which is one thing else I discovered from this video.
