I have two enging codes. What to check

[particlewave]

How much do you want to bet that the air pump is working?

Why would you get an "air pump does not work" for only one bank? Clogged ports maybe, but other than that, you wouldn't.

Many have had these codes (myself included) and it's almost always a bad changeover valve or a vacuum leak. I'm going by real world experience and don't care what some incorrect book says.

Either way, you use logic: these codes are triggered by incorrect voltage at the pre-cat O2 sensors (0410=bank one, 1411=bank 2), meaning that there is insufficient airflow at the indicated bank(s) during SAI cycle.

[JFP in PA]

Originally Posted by particlewave

How much do you want to bet that the air pump is working?

Why would you get an "air pump does not work" for only one bank? Clogged ports maybe, but other than that, you wouldn't.

Many have had these codes (myself included) and it's almost always a bad changeover valve or a vacuum leak. I'm going by real world experience and don't care what some incorrect book says.

Either way, you use logic: these codes are triggered by incorrect voltage at the pre-cat O2 sensors (0410=bank one, 1411=bank 2), meaning that there is insufficient airflow at the indicated bank(s) during SAI cycle.

The codes say it is not working for either bank. And that "incorrect book" is the factory OBDII manual, written by the same guys that programmed the DME............................

It is also easy enough to find out if the pump is working or not.

[boxfix]

I had the same problem and it turned out to be a huge vacuum leak.

the Vacuum reservoir failed on my 2003. I also had the check valve that inserts in the manifold to source the vacuum fall out.

So I had very little vacuum to run the SAI system and the other items actuated by this vacuum system.

Get a vacuum gauge. Insert it into the system with a "T" connector and see if you are getting 15 to 20 " Hg reading. I was getting close to nothing in vacuum.


Next test the reservoir. Hook a hand vacuum pump with gauge directly to the reservoir. See if it will hold vacuum. If not replace the reservoir......they cost about $20.00. The reservoir is made in 2 pieces and glues together. It is a common failure that it becomes unglued. Mine would hold no vacuum. You do not have to un-mount it to test it. Use long needle nose pliers to remove the rubber fitting and attach a hose from the tester.

Look at all the vacuum lines. The lines are plastic with rubber connection pieces. the rubber ages and cracks. I have replaced as much of the Porsche vacuum lines as I can reach with 4mm high temperature silicon hose.

There are several good vacuum posts on this site.

Keep us posted and ask lots of questions. Particlewave knows his stuff!! He helped me a LOT!!

[boxfix]

Originally Posted by JFP in PA

The codes say it is not working for either bank. And that "incorrect book" is the factory OBDII manual, written by the same guys that programmed the DME............................

UMMM I don't know about that source.....

BUT I do know that PARTICLEWAVE is right.

[JFP in PA]

Originally Posted by boxfix

UMMM I don't know about that source.....

BUT I do know that PARTICLEWAVE is right.

Fine, then listen to him and let me know how you make out. But the answer I gave to the original poster is correct.