P0410 1999 E320 V6
 

I've researched & troubleshot the system. MIL was coming on after as little as 50 miles with a few engine-offs in between. P0410 comes up each time.

Here is what I found;
1) air pump is fine, blows strong at start-up
2) vacuum solenoid works fine, vacuum at both check-valves & both check-valves work fine
3) O2 sensor seems to be functioning as it should.
4) R&R'd both check-valves and both ports into the head were clogged with black crud.
5) picked out crud w/a small jewelers screwdriver then blew out resultant crumbly bits w/compressed air
6) passages are clean for the short length I can see but I have no idea how deep they go & how many twists & turns there are (is there a head cutaway pic somewhere?) so I do not know if the clogs continue deeper into the head (I suspect they do).
7) Reset the MIL & ran the car for over 50 miles then got it tested
8) it failed due to "readiness"
9) MIL came back on when I started up the car to leave the emissions shop.

So I have a few Q's.
1 - How far does this car need to run before the computer readiness toggle clears?
2 - If I spray throttle body cleaner down the ports, do I risk killing the CATs?
3 - Will spraying out the ports help or are they so twisty it would be an exercise in futility?
4 - If I do spray them out, should I do it with the engine off or running?
5 - Can I clear the ports with a long bushy wire implement such as a pipe cleaner?

Thanks in advance...

P0410 Error
 

Hello,

I had this check engine light on my S500 and fixed it. Through my research, people have replaced o2 sensors, spark plugs, air pumps, throttle body, and air check valves. I had this check engine light over one year, and I have replaced most of the items listed above by myself and finally fixed the problem. The problem was with the air pump, after I replaced it everything I have never seen the check engine light on again. You should take it out and test it, just add positive and negative, it should blow wind.

Well, that is the code for the air injection system failure.

There are several protocols to use at different times. My rule of thumb is three drives of 20 min/20 mi or more and until the engine has warmed fully. The engine should be a allowed to cool back down in between drives. At least that worked for me. Of course, if you still have faulty air pump the code will come back regardless.