yaris P0420

Yaris girl · **Joined:** Thu Apr 30, 2009 10:33 am **Posts:** 2

Hi, I have a Y reg toyota Yaris 1.0. My engine warning light came on and I've had two diagnostic tests done - both coming up with the P0420 code.

I recently (Feb) had a full exhaust system replaced (including the catalytic convertor) and about a week later had a service and MOT which were fine. The MOT emissions test passed.

Is there anyway of knowing what the problem is? The cat convertor is under guarantee but I'm concerned they might 'find' a different and expensive problem.

Thanks!

Sponsored Links · **Joined:** 29 Jun 2004 08:12 pm **Posts:** N/A

phllbit · **Joined:** Sun May 17, 2009 10:53 pm **Posts:** 4

Judging by the information you have given so far i.e. you had the complete exhaust changed, p0420 would refer then to one or more of the oxygen sensors which are located at either end of the catalytic converter.

Did you have the work on your exhaust done at a Toyota dealer? If so, straight back to them with the problem for this should not happen IF the work done on your exhasut was performed correctly. If the work was done elsewhere, this may not be a good scenario for if the exhaust is correct, then there could be another problem such as computer issues but I doubt that.

These oxygen sensors are a pain so I am guessing that when they changed the exhaust, they did not renew the sensors as you would for a vehicle of your age for the very reason that now a few months down the line, they are playing up.

Yaris girl · **Joined:** Thu Apr 30, 2009 10:33 am **Posts:** 2

Thanks for that! I've been back to the garage and they've changed the catalytic convertor for free and the engine light hasn't come back on so far - that's over a week now. Hopefully that's it but if not I'll take it to a Toyota dealer.

jeff compton · **Posted:** Mon May 18, 2009 12:40 pm

Im very doubtful it's an 02 issue unless they were damaged from the exhaust work and don't be suprised if a new aftermarket converter turns the cel on when your old orignal one did. New doesn't mean good alot of the time with converters and just because it will pass a tailpipe test or even keep the cel off occassionally doesn't mean the calayst brick inside works well enough to last as long as your toyota converter did originally.

yaris P0420

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