P0422 - 2001 Elantra

Hi Hyundaitech!

You probably don't remember my unrealistic optimism that P0422 might
only be an O2 sensor problem, from a post in June, which you helped
bring to ground. (It still seems weird to me that the car would be
diagnosing a bad cat so soon after getting perfect marks on a smog
check).

Well, if I am to bite the bullet, do I need to replace both Cats? In
yet another display of optimism (do I never learn...), I'm hoping I
can get away with replacing only the exhaust manifold+cat for a mere
$161, and not the front pipe+cat, which runs $743. Yet my gut tells
me that the more expensive one would be the more important one, and
(unless I'm having a brain fart) they're both between the upstream and
downstream o2 sensors.

Thanks!
-Matthew

 

Unless your car has a different setup than most I've seen-- that's possibl
since different localities have different emissions setups-- you have on
oxygen sensor in the manifold prior to the manifold converter and one i
the front pipe behind the manifold converter and in front of the rea
converter. I've seen no vehicles (of your vintage) with a sensor behin
the rear converter.

So, it'd be my assessment that you only need to replace the manifol
assembly (which includes the front converter).

Also, if you're the original owner, you may be able to get this covere
under the powertrain warranty -- exhaust manifold is included.

And, you may also have an open recall on the manifold which allows th
dealer to replace it free of charge if it's cracked. (In my opinion, thi
is the reason it's being sold so far below what most would consider
reasonable market price. Dealers buy from Hyundai and sell back afte
their allowed markup. Hyundai would like to minimize the markup expense.