REading 2006 Sonata check engine light code

I agree that's a little odd. Normally, trouble codes remain for
longer than that, even after the lamp goes out, unless the battery
went dead or was disconnected.

Most faults require two successive failures to turn the lamp on, and
then three successive test pass results for the lamp to be turned
out.

Certain important faults will set the lamp at the first fault.

If there's only been one fault, the code is stored as "pending" and
will be erased if the next test passes. I suppose it's technically
possible that this was an important fault that only occurred once.

Of course, it's also possible that the technician didn't check all
necessary systems (engine and trans) or for whatever reason decided
the thing to do was to clear whatever the code was and simply deny its
existence since the check engine lamp was on.

 

I wonder if there's a problem with your fuel sending unit. Can't
remember off the top of my head whether it's monitored by the ECM.
Numerous problems with these in early production '06 Sonatas.

 

Okay, skip the sender idea. I'm guessing you have a leaking intake
manifold gasket. Have done a few of these on 4-cyl '06 and newer
Sonatas. This would explain the roughness as well. In fact, it's
usually obvious if you remove the plastic engine cover and look
around.

 

Yep, that appears to be it. Any idea why this is a common failure mode?
I've never before had a vehicle where the intake manifold gasket
failed and I've run several cars well over 100,000 miles.

Is the replacement gasket better than the original? Do I need to plan
to replace this every 50,000 miles on this engine?

Matt

 

My only suspicion is improper torque from the factory, either too
loose allowing the gasket to get sucked in, or too tight, damaging and
weakening the gasket so it can get sucked in. Usually, a portion of
the gasket indeed gets sucked in. I don't see enough failures to
expect that all cars will have it, just enough to know that with
certain symptoms, this is an excellent first place to look. In my
opinion, the gasket is stout enough-- a couple layers of thick paper
like most intake gaskets. Have seen no difference in construction
between replacement gaskets and the originals.

 

Have you had a hard time getting the gaskets? It has been two weeks
(last Thursday) since the dealer ordered mine and it has yet to arrive.

Matt

 

They finally got the gasket today. Have it installed Wednesday and hope
that really is the problem!

Matt