Crl p0420

[stevobags]

Strangest thing happened to me. The CEL came on and it read P0420, bank 1 upstream issue. So there I am, damn what to do. I do my reading as I always do and decide to run it before I undertake any work.

Throw a bottle of Techron in and fill her up.

The car is filthy with salt from the roads up here in NY. This baby needs a cleaning so off I go the self serve car wash. Just wanna take off the salt, no major cleaning job today. I spray and I spray.... Make sure I get the undercarriage, I mean I spray the hell out of it.

Go to work this am, CEL is cleared. Twilight Zone?

All the best! Let you know if it comes back on.

[2010exl]

P0420 is for the catalytic convertor, bank 1.

It's reached the end of its useful life and is triggering the "catalyst below efficiency threshold" code under certain conditions.

You may notice the light coming on and off over the next few weeks or months, but eventually it will stay on all the time.

What year and how many miles are on the Pilot? I believe the convertor has up to an 8 year 80,000 mile warranty. Check you warranty book to verify this.

[stevobags]

Thanks! 2005 EXL. 148,000. The cat is in the front, correct? For some reason I always thought it was in the back (maybe way back when).

[rocky]

Cats are always closest to the engine


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[2010exl]

Very close to the engine. They are bolted directly to the cylinder heads. There is also a third catalytic converter downstream but its not monitored by the ECM.

[stevobags]

Appreciate it all!