CEL Problem Persists Depsite Repairs
 

I have a 2001 S. Several months ago, the CEL light came on with codes P0410 and P1411.

So far, I've done the following: 1) 90K service. 2) replace inoperable solenoid in passenger bank variocam, 2) replaced all valves and vacuum lines in secondary air ssystem, 3) replaced the air oil separator and its breahter hoses. The computer suggests the MAF and O2 sensors are operating within proper ranges. The air pump seems to work ok too.

Still, after each repair, the CEL popped back on. It always happens when the car has just started. After driving for a couple of minutes and less than a mile, I'll look down and see the CEL.

Anybody have any suggestions where to look next. I'd appreciate any suggestions.

Thanks

mileage? New error codes?
Here is a good ts guide for your old codes:
http://www.renntech.org/forums/topic/628-obd-ii-codes-p0410-and-p1411/

Thanks. Milage is rougly 90965. According to the mechanic - no codes other than P0410 and P1411

Sent you a PM.

Regards,
paul...

Thanks Paul for the follow-up.

The shop has worked its way through the entire flowchart and all things check out. Unless it's an intermittant electrical issue starting the air pump, it seems the only other thing to do is start replacing parts the computer says are working ok, i.e., the MAF and O2 sensors.

I would try cleaning your MAF first before replacing it. CRC makes a MAF spray cleaner. It's an easy job to do yourself. The MAF is easy to get at right next to your air filter.

Had the same exact codes. 2 cleanings of the MAF made it stop for a little while and then I finally got tired of it and replaced it. Voila. No more CEL.

Have you replaced your gas cap lately?

Now that you ask, I did replace the gas cap. Could the new cap have something to do with the CEL continually returning?

Is it OEM?

It needs to be factory original otherwise you could have problems.

Hmm, these are tough to narrow down. I would perhaps think about doing a smoke test to find possible vacuum leaks. At least that will eliminate them as a potential problem? I've got an article on this procedure here:
http://www.pelicanparts.com/techarticles/Boxster_Tech/21-FUEL-Vacuum_Leaks/21-FUEL-Vacuum_Leaks.htm

-Wayne

If for some reason you decide to replace your MAF sensor, send me a pm and I'll share with you my experience with finding one on the cheap .

I had the same problem. The trouble shooting list is quite long for the SAS and I got tired of taking the car back to the shop every time the P0410 and P1411 codes popped up.

My "fix" probably won't work for you in Cali due to more stringent test procedures, but it will work for others who have this problem of CEL with a car that has no other symptoms of poor running:

You can reset the DCM to ROW (rest of world) settings which makes a few changes to the car, one of which is ignoring the SAS system. Your CEL works normally at start-up, but wont throw a code for P0410 or P1411. It also gives you a few more HP and you can start the car in neutral without pushing in the clutch pedal.

I don't know if they plug into your OBD port and read your tune in Cali or not, but no one could visually tell you had this done by looking at your car when it starts and runs.

Assuming the error codes are the same, your issue is centered around the secondary air injection and not the MAF. Sounds like either clogged tubing or a vacuum leak. Keep digging. Changing out unrelated parts might be fun but it won't fix the problem. Whenever I get stumped I always ask "what am I missing". Sticking stubbornly to the process of elimination works.

Wayne! Dude! Where have you been? You have been a member since 2007 and I am now just seeing a post from you on this site? You need to visit more often; there is a great group of Boxster enthusiasts on this site. BTW your book 101 Projects for Your Porsche Boxster has been very helpful.

Hope to see you post more often.

CEL Problem Persists Depsite Repairs
 

Thanks everyone for the advice so far.

After the last round in the shop, the CEL popped back on the first start after 50 miles. All the secondary air parts have been replaced now. So I am beginning to think its one of the O2 sensors. Two questions. First, with a 91K car, can an oxygen sensor be bad without throwing any of the codes. In all time, no O2 code has ever been seen although the mechanic once mentioned a sensor was slow to react. Not sure how he knew this. If yes, is there any way to tell which sensor may be bad? Second, is it true that after resetting the codes, the car's computer waits for 50 miles until it checks again for CEL related codes. Thanks

I thought Wayne owned this web site now ???

99 w/ 90k same problem until ....... no more mid grade, only hi-test and B12 gas treatment and no more light for over 600 miles. was told mid grade was OK but kept getting the "light" on and off. Best of luck as I share your pain.

I think change O2 sensors. I have a similar prob on my 00S. Try turning the key to "on" to allow the sensors to Warm up for a minute or so before starting.

Well, changing the O2 sensors did not solve the P0410 and P1411 codes as many said it wouldn't.

So let me ask another question. I've looked at the secondary air system diagram and all parts are new and the hoses don't have vacuum leaks. So if a leak isn't there, where might I look to see where else can it be? I'm guessing that the vacuum is created in the intake manifold. What lines or other systems link to the secondary air system to provide vacuum there. I've replace the AOS as part of my CEL odessy.

Thanks