Coming home from work and enter my street; on pops the CEL. I hook up the OBDII and the great P0410 comes up. I did lots of searching on the topic but want to give brief history and make sure the next step check list is still valid.
Car has 125k, burns about 1 qt every 1k - 1.5k. At 70k a complete engine reseal was completed by PO (cyl head gasket, rod bearing as well as crankcase due to corroding?).

Anyway, the car has been running great for the past 55k. The previous posts list the following as first "to does" prior to the flush or guide replacements:

Check valve
SAI valve switch are these 2 the same thing?
Cut off valve?

Anything else? Also I cleared the code and have about 50miles and so far no light.

Thanks

Pat

 

Don't be so quick to jump to conclusions just yet.

There's tubing/connections on "THAT" side of the engine (by the SAI valve) that, if loose etc., can cause the exact same code to appear.

Check the simple stuff first.

G.

 

With that many miles, I am 90% confident that your SAI valve is bad.

There are two items that you may need to replace, (1). SAI one way valve, (2). Check valve.

You can test the function of the check valve once you have yanked them out of the system with a hand held vaccum pump. They are both around $70 each.

If you have a bad SAI valve, the CEL may not come back on from the first cold start with error, generally after the 2nd or 3rd consecutive error log then the CEL will turn on.

There is a brief explanation of the SAI valve and the check valve from the 996 DIY section of my site. http://p-car.com/996/diy/sai/mainpage.html

 

As always, thank you for the input. I will likely attempt when I have a free weekend as I think this one will take me awhile to do myself.

Thanks again.

Pat

 

I suspected the worst on my car also. happened at 70k+ miles.
Check valve stuck. replaced it, 6k miles ago. haven't had a problem since.

 

Did you do the replacement yourself? or did you have a shop do it? (cost?)

 

tam993,

Did you also attempt to clean out the ports; or did you just replace the check valve? If so, what cleanout technique did you follow?

 

Hopefully, it's just the check valve, with no clogged ports. My valve was shot, but the car otherwise got a clean bill of health.

Good luck!

 

I did the repair myself (with the help of this list of course). the check valve was rusted big time and frozen in place. i.e. the valve didn't move. This is something you can check yourself. First check the one valve
up stream from the valve that's in the manifold and its connections, make sure the blower is working properly and then pull or check the one way valve ( i guess thats what it's called).
I removed mine, fashioned a air coupling to it and then checked the ports to see if they were clear. Not knowing how much the air flow should be I removed the heat exchangers too. most of the ports were opened a couple didn't flow as well as I thought they should. So i used solvent and air pressure from both sides of the port. I also separated banks so I'd only be dealing with 3 ports at a time. took me a couple of weeks screwing around with it to get to the point were 125psi would blow through them all together.... and no more crap blew out with the solvent.
the exhaust valves looked in pretty good shape ( not much in the way of build up ) and the engine runs around 2k miles using about 3/4 qt. there wasn't any way I'd do a top end rebuild on a factory engine at that point.
I also used a small steel cable to see if the ports were clear but it didn't do much of anything. High pressure air did it. but the SAI ports were really not that bad. I think the valve caused the problem
more than anything getting stuck and not closing all the way or opening all the way.
i changed a valve cover gasket while I was under the car and replaced some bolts and things
the valve was like $50 from Sunset and the gaskets for the exhaust were like 6 bucks each or something. It wasn't very expensive to get done if you do it yourself, which I suggest you do.
there really isn't anything you can mess up too bad. People on the list will help you. Do a search, there is a lot of info on this list. Make damn sure you check what's going on before you let anyone talk you into dropping that engine.