cpdjfd107

Yesterday I got the CEL and I checked the code with my OBD reader it showed P0401. I did a search on Rennlist but got nothing. OBD says it is EGR valve. Is this something to do with SAI? I thought that code was 410? Unless I read it wrong, but I'm pretty sure it was 401. Any one here with any ideas?? I was on highway doing aprrox 70-75mph. Oil temp was at 8 o clock. I lost nothing in performance. I reset it last night and did not come on yet from todays drive, short 5 miles highway trip. Strange thing happened during drive though. My Rs clutch and LWF was causing stalling issues. When I went for that drive, the LWF wasn't dropping revs as fast as it was prior and car was much easier to launch from a stop and stop. Is there a relation? Any info would be helpful. TIA.

Deadeye

Chris, are you sure it's not 0410? I don't see a 0401 code in Streather's book. 0410 is indeed an SAI code so hopefully that's NOT what you have. I'm in the process of trying to flush my ports and I'm not having much luck do far.

trophy

IIRC EGR stands for Exhaust Gas Recirculation. I couldn't find a reference to anything EGR related in the manuals. As the OBD readers sometimes have generic terms for issues (rather than vehicle specific) it will take a bit of interpretation.

Could be something related to the Tank venting valve, or other vacuum systems. good luck Sorry i couldn't be of more help.

cpdjfd107

I'll see when/if it happens again. I don't burn much oil. My oil usage is very low. So maybe just carbon build up? EPE just replaced my SAI check valve a few weeks ago. So I would hope it is not already clogged. I didn't get CEL on this prior to service and changing out the check valve. I'm not worried about the OBD and emissions testing. The place I go to noticed my car was All Wheel Drive so they just do the sniff test in the tailpipe.

Deadeye

Unfortunately it's not the SAI check valve that cloggs, it's the stupid passages Porsche put into the cam towers and heads that get clogged up over time. My car uses a 1/2 qt. every 2K miles and runs like a top, but the ports are plugged. If the car burned oil, leaked oil or ran like crap I would do a top end job, but it's a shame to disassemble this engine for the stupid SAI ports. Do I sound bitter?

jaholmes

I'm sure its the SAI port CEL. Some scanners throw different errors that you have to cross reference to get the right description. I know mine threw the code and it had a code for the right and left.

Get out the hoppes #9 and a base guitar string.

cdmdriver

https://rennlist.com/forums/993-1995...t-you-can.html

It's a pain in the a$$, but definitely doable as a DIY. Above is the link to my SAI repair.

Sonic dB

Thanks cdmdriver for your tutorial. Your tip on using the brake cable works, it was the only cable that worked with my car. Also one thing that I did was disconnect the feeder lines from the SAI housing, and then flow the B12 through those in order to seperate each bank of 3 cylinders. I tried the same drain stoppers that you used, but they soon turned to mush due to the chemical flush, so I just went without after that.

cpdjfd107

Well I'll wait for it to come on next time before I consider a DIY with the guitar string or brake cable. But like Deadeye said, my car uses virtually no oil, runs great, I have a shop that passes my car easily due to it being a C4. (I think they are wrong on the AWD thing, but I'm not going to argue!!) So, should I really even go through with the DIY or just reset the light as needed?

Ed Hughes

As I research my possible 993 purchase, this is great info, particularly cdm's fix. I hate it though.

I really want a C4S, but the '95 C2's are so attractive to avoid CEL. Decisions, decisions.

cpdjfd107

I forgot to mention that this is the first time I got this code, and previous to getting the CEL I added a bottle of Lucas fuel additive upper cylinder lubricant a few hours prior. This was the only time I ever used this Lucas stuff in my 993. I normally use Techron, but I figured I'd give the Lucas a shot. I use it in other vehicles without problems. Do you think there is any relation of Lucas upper cylinder lubricant and CEL?

Sonic dB

The Lucas probably had no effect on it. This is a cumulative effect of carbon build up that most if not all 993s will eventually go through. On my own car, I purchased with 78K on it and it didnt throw the CEL for this code until 115K... so Im taking care of it now... and I plan to selll it soon and want to make sure that this car is as clean as possible and worry free for the next lucky owner. Anyway, IMO... do the SAI clean yourself, its not that bad and there are a ton of great tutorials on it here at the rennlist. If I were to keep my car, Id do this every 30-40K as maintanance.....once you know how the system works its no biggie.

Ed Hughes

^^This is reassuring. Probably a good time to bond with the underside of the car too. It's always good to spend some time under the rear of a 911 (993, 964, etc).

cdmdriver

Thanks Sonic, I love to hear the success stories using my SAI DIY. I have also been contacted directly by a few other great Rlisters seeking reassurance before diving in. So far everyone that has done the SAI clean out using the bike brake cable has been successful. It is not that big a deal. I firmly believe that this problem is caused from a faulty check valve allowing air to flow the wrong direction through the SAI ports. I have also noticed that this problem seems more prominent in areas with high humidity. Moisture mixes with the exhaust in these narrow passages and over time builds up. When I first changed my check valve, water droplets came out of the valve.These air passages just need to be reamed out periodically.

Sonic dB

Yes cdmdriver, your tutorial and also your reassuring attitude that 'anyone can do it' really helped....also there is a thread here from "Mike" I think...where he shows how the SAI system is put together with photos and info from his engine rebuild. It can be found with a search, and he also posted it here:

http://www.pcarworkshop.com/index.ph...e_SAI_passages

The Brake wire is cheap and was the only thing that worked on my car. I now have 5 ports flowing very very cleanly and the 6th one Im going to finish up this evening and then put everything back together tomorrow.

The drilling with the brake wire is the key, IMO....and with a couple of ports you may need to sit there drilling for a while, not knowing if it is working or not but it is.... once you get that wire up about 5 and a half to 6 inches inches up the port, then you are pretty much up to where the port meets the intake port for the SAI...after that the flush cleaned up all of the crap and that flows out pretty easily.

The hardest part was removing the check valve,....I ended up grinding it down and using a 27mm socket on it, but I still had to use a mini torch and it broke right free... BTW...you are correct, my check valve was TOAST...the internal mechanism was completely worn away and it was stocked with carbon in it... it basically was a 2 way valve and obviously wasnt doing what it was designed to do which may very well have had an effect on the carbon build up as you noted.

If I had to do it again, Id just use the mini torch and vice grips on it from the start and I have a feeling that it would break free without having to grind it all down....anyway im glad its pretty much over...thanks again....