What do Codes P0420 & P0322 mean how do I fix it?

SPENCEB

MEMBER
2002 VOLKSWAGEN JETTA
4 CYL
2WD
MANUAL
150,000 MILES

Car starts sluggishly, during shifting or driving RPM can't go above 4000 because then it shuts down. Check engine light on. SOMETIMES, idling at a stop with AC on, the engine will shut down. Code computer says Ignit/Distrib -Engine Speed Circuit no signal* Is my crankshaft sensor bad or do I need a new catalytic converter?

1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

The P0420 is saying that the converter on the exhaust is not reducing the emissions to the proper level. This is called a cat inefficiency and normally you need to replace the converter.

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

https://www.2carpros.com/articles/repair-lean-mixture-codes-p0171-or-p0174-on-some-manufacturers

Basically if the engine is sluggish as well, then I suspect the converter is plugged.

I would start with this code and then see if the P0332 which is a misfire code indicating the ignition system is the issue, but that may clear up once the converter is fixed.

I would pull an upstream o2 sensor and find out if the engine runs better than that shows that the exhaust is restricted.

I attached the info below from the manual that will help with replacing this.

Please run through this info and let us know if you have other questions.

Thanks

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