Hey Fellas/Ladies,

So, I was chasing the dreaded P0410 Code on my wife's '05 CLK320 W209 M112 engine with 197K on the clock.

Secondary Air Injection System (SAIS) fail code and will not pass Smog Check.

Used a MityVac Diagnostic Tool, Voltmeter and OBD2 Reader, Checked all the usual suspects, lazy O2s, relay, vacuum lines, switches, air pump and it's hoses, ZERO Luck. All functioned as designed.

Scoured thru YouTube and all the Mercedes Forums. Found two possible options/ideas:

1. Remove the Check Valves from the Intake Manifold and hope the tip insert of valve does not snap off or Open Up the top half of Check Valves.

2. BenzWorld had an interesting thread about using a 1/16th diameter braided steel cord and a drill to use it as a snake/auger to clean out the SIAS Check Valve port's internal route to the Exhaust Manifold.

I opted to open the valves and to my amazement besides the expected carbon residue/build up there was a literal 1/2" round carbon ball rolling around inside Passenger Side (P-Side) valve lower half with the neck under the reed flap. Nice, but not the culprit. After cleaning, I used the MityVac tool and discovered the ports were completely clogged down the line.

I proceeded to use the cord by hand was able to fish and twist my way down the line a little over 6 inches on the Driver Side (D-Side) but only 5 inches on the P-Side. Tested with MityVac, D-Side was not holding a vacuum ergo cleared but P-Side was still clogged. Used the drill method, it failed and the cord just bird's nested.

So, I needed something more rigid yet thin and flexible as not to bird's nest or worse break off in the port route. Then I remembered I had some left over nickle plated solid cable for my '85 Porsche heater lever cable replacement.

I took about 15" of it and bent a handle at the end of it to mimic an auger to be able to twist and turn the open end of the wire within the twist and turns of the SIAS Check Valve Port Route/Line.

At first it was a struggle feeling the way thru the ridiculous route but managed to fish and snake to almost 90%+ or the same 5" of the P-Side route. Yes last critical 10% was a dead end, I assume it was full of carbon build up.

To help soften it, I used a little bit of brake parts cleaner spray and filled up the port/neck, fluid did not budge, it slowly evaporated.

Frustrated and dreading the fact that I may need to remove the exhaust manifold to get to the route from the back end, I took the open end of the cable ( straight tip ) and placed a curved 15-20 degree bend.

It sorted of worked, but it was easier to pass thru the bends more freely without sticking as much on the rough edges and castings and dug out some carbon when I pulled it out but still could not pass the last 10%.

What to do, what to do, so I bent the tip further to a 45 degree curve (curve liken to a dime).

Voila! That was it! The last remaining turn was passed and line cleared. Vacuum test did not hold.

I used a portable electrical air pump, a rubber plug with a ball inflator tip and passed air thru the port/route.

Cranked the car couple of times to help push out any potential carbon debris/dust then started the engine, the SAIS Pump kicked on and for the first time did not sound strained/blocked.

Here is the tool, I may post a YT video on how to use it.

I hope this will help someone struggling with the dreaded P0410 idiot code. I call it idiot, because it's sole function is to pass Cali Smog.

Cheers,

Jim

Attached Thumbnails

   

__________________
05 CLK320 Cabrio
85 911 Carrera Targa
96 Lexus ES300

Update: Did the Drive Cycle, the SAIS passed :-), next going to the Smog Test Facility.

__________________
05 CLK320 Cabrio
85 911 Carrera Targa
96 Lexus ES300

I need to go thru this on a E320. If you do post a video that would be great.

Here you go, sorry for the poor quality, Hope it helps.

__________________
05 CLK320 Cabrio
85 911 Carrera Targa
96 Lexus ES300

Great info, thanks,

You are most welcome and break a leg on the Clean Out.

__________________
05 CLK320 Cabrio
85 911 Carrera Targa
96 Lexus ES300

No video, but this BW thread covers my experience in eliminating the P0410 code on our ;98 W210 E320. (Most toward the end of the thread). The OBD app I used was a neat way of showing the 2ndry air system was functioning.

https://www.benzworld.org/threads/p0410-questions.2993841/

__________________
Graham
85 300D,72 350SL, 98 E320, Outback 2.5