Pesky CEL

99box · 06-03-2013, 08:14 AM

Hello,

I would like some advise on a pesky CEL that will not stay out on my 99 Boxter tiptronic (103k mi). I am getting OBDII codes P0446 (gas tank vent), P1124 (run lean cylinders 1-3?) and P1126 (run lean cylinders 4-6?). This started this past winter when it was raining (don't know if the rain had anything to do with the problem). Mechanic has changed the MAF 2 times, O2 sensors, AOS, gas tank vent solenoid, spark plugs and coils. He smoke tested the intake and crank case and found no leaks. I can not afford to replace any more parts. Here are the symptoms with the codes reset; I can drive the car for about 25 miles and then when I am sitting in stop and go traffic the CEL will come on (codes P0446, P1124, P1126). The car seems to run fine otherwise. I can reset to the CEL and repeat the same process. Anyone solve this problem before or have trouble shooting advice?

NewArt · 06-03-2013, 02:47 PM

Have you inspected/changed you gas tank cap? Any cracks around the gasket? I had a similar problem and this solved it!

99box · 06-03-2013, 04:07 PM

Thanks for the advice but the gas cap and o-ring looks good. It does not have any cracks.

matt demaria · 06-04-2013, 07:10 AM

1124 & 1126 are codes for being too rich.

99box · 06-04-2013, 08:28 AM

P1124 & P1126 are codes for fuel enrichment limit reached at O2 sensor. Another words the fuel injection system can not add any more fuel to the air mixture (run lean). This how it was explained to me from my mechanic and the Porsche Dealer service department. It seems I have a problem with the gas tank vent, venting too much air to the intake, but I can't find the leak.

jwgn777 · jwgn777's Garage

Try checking your lines and canister behind the right wheel house cover. You might as well you have check everything else. What fuel cap is on your boxster? The black plastic one or the zinc coated metal cap.

99box · 06-05-2013, 10:10 AM

I looked in the front passenger wheel well once but didn't see anything wrong. I couldn't tell if all the valves were working properly or if there was a problem with the charcoal canister. What is the best way to trouble shoot this area with basic tools and compressed air?

99box · 07-15-2013, 08:47 PM

The car is gone. Biggest mistake I've ever made. The CEL never got fixed after dumping over $2k into it. The odometer light on the dash board never worked right and stayed on draining the battery. Stupid car that can't be fixed. I finally traded it to a dealer only after 16 months of owning it. Now it's someone else's problem. Porsche is a POS.