kambam3627

2000 180K, just out of curiosity has anyone used the “oxygen sensor spacers “ to clear the CEL light? And did you put them before cat or after cat? My code reader doesn’t specify if before or after cat just says bank 2.

Superfast1

Code P0430 Bank 2 indicates your catalytic system efficiency is below threshold on bank 2 so your problem could be 1 of these 3: Intake air leak, faulty downstream O2 sensor and/or faulty catalytic converter. Here's what you should do: Check & listen to any air leaks around your intake manifold. If no air leak then hookup an OBDII scanner & check the voltage at the downstream O2 sensor on bank 2. Unlike the upstream O2 sensor where the voltage is switching from .1V to .9V (rich to lean condition & vice versa), the downstream O2 sensor voltage should remain constant at around .5V. If it's also switching between .1V to .9V then your cat is worn out & in need of replacement. If you don't get any voltage reading on the upstream nor downstream O2 sensor on bank 2 then the respective O2 sensor is faulty so check & report back. Good luck.

Giorgio13

I have used spark plug non foulers and had success clearing the P0420 and P0430 code. Go to amazon and search oxygen sesnor spacers, they have quite a few to select from. I used dorman spark plug non foulers and had to drill one out with a 1/2 inch drill bit but if you find an angled one on amazon then you may not need to do the drilling. I installed the 02 spacer after the cat. Good luck and please share you results with pictures if you can. Thanks.

billydpowe

iTrader: (1)

sounds good to me

Banshee365

I still fight a P0420 in my car. I haven't looked much into leaks in the intake circuit. I do hear a slight hiss when I put my head near the engine at idle. If a leak can cause these codes I bet that is just what is causing mine. About everything else is ruled out for me. I've had these codes with this same engine in two different cars, two different exhaust systems, two sets of 02 sensors and two different ECM's.

Superfast1

Get a bottle of carb cleaner (not starter fluid) then spray around. If the engine rpm drops then you've found the leak. Good luck.

jaaa

I've had both 420 and 430 codes in my 1996 ls400, and they were both caused by leaks right at the flange on the joint past both cats. Once I fixed the leaks, both codes went away. I did some research when this happened and found a leak there is quite common on these cars.