What tools do I need?
After clearing codes and reliable running the federal test procedure (aka the "Drive Cycle"), I can set all registers but I'm getting the dreaded P0420 Bank 1 (cylinders 123) catalytic inefficiency OBDII code on a 15 year old dual-cat vehicle.
Do you have experience troubleshooting a P0420 cat inefficiency code? a. Most likely, from what I've read, it's the cat b. Sometimes, from what I've read, you can clean it c. Most people, willy nilly, replace the downstream lambda sensor
Both downstream oxygen sensors are original, as is everything else other than the upstream O2 sensor, both of which were replaced recently to allow the I/M readiness monitors to be set (it worked for that purpose).
The original problem "may" have been the CCV, which was broken in half, but that original condition has been repaired.
From what I've read, the P0420 resolution & debugging tools include:
- Buy an OBDII tool that can show the downstream sensor voltage barely fluctuating while the upstream sensor fluctuates at warm speeds.
- Switch the two secondary lambda sensors & run the test above again.
- Buy a five hundred degree F infrared temperature sensor that can show the delta between the cat input & output.
- Use a mallet to hear for flaked off components making noise inside the cat.
- Buy a gallon of liquid lacquer thinner (mostly acetone) and pour it into ten gallons of gas (Scotty Kilmer ).
- Use laundry detergent and soak the cat (Scotty Kilmer - see above URL).
- Buy sodium hydroxide (2:1 by weight) and soak the cat (Eric the Car Guy
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- Hail Mary play and replace the secondary oxygen sensor.
- Hack methods include adding spark plug spacers (dunno if it works).
- ??? any advice what tools I need to properly diagnose & repair ???
Note: The cat appears to be bolted on. It's a 2003 BMW 525i, where
*something* is different in NY or CA since most places won't ship to these two states but will ship to the other 48 states. Why?What tools do I need?