CEL-no symptoms?

[particlewave]

It was really cold out tonight, only about 5°F. My fuel line froze up my daily driver, so I got the Porsche out for a quick run. I started it and went to open the garage door, but the door was froze shut. I let it idle while I manually opened the garage door...couldn't have been more than a couple minutes. When I got back in the car and up the highway a bit, I noticed that the check engine light was on.

My question is, do you think this could have been caused by fumes in the garage or the cold? It seems kind of odd because the car has always ran great and was running great tonight...no symptoms.

[Kenny Boxster]

The surest way to know is to read the code generated by the CEL. It may not even be related to the cold or the fumes. If you do not have a code reader/durametric/ or even PIWIS, simply pull into any auto parts store such as autozone and ask to use their code reader for free. Hope that helps!

[particlewave]

Ah...I thought the code could only be read by a specialty reader. So an OBDII reader could read it?
Thanks Kenny

[JFP in PA]

A standard OBD II scanner can see most codes with the exception of ABS, Air Bags, PSM, and other "protected areas" that Porsche does not want "outsiders" messing with. Those require a PIWIS or Durametric system to access.

[l3m]

Might be the fuel. This happened to me once. Didn't drive the car for two weeks. Got a CEL once I got on the road. After the next fill up, it cleared up.

[paulv]

Originally Posted by particlewave

Ah...I thought the code could only be read by a specialty reader. So an OBDII reader could read it?
Thanks Kenny

If you go to a parts store to have the code read, ask the person if the code reader has freeze frame data available (some don't). If so, get the RPM, Load%, short and long term fuel trim values and post them here.

BTW, the slope of your equation is 7/3, y-intercept is 11/3, and that's about what I remember from my school algebra!!

Regards,
paul...

[Flavor 987S]

Need to read the code, as stated by others. Could be as simple as a loose gas cap or oil fill cap. Check those things first.

[Flavor 987S]

Originally Posted by Flavor 987S

Need to read the code, as stated by others. Could be as simple as a loose gas cap or oil fill cap. Check those things first.

Really, a frozen fuel line on the DD? I thought that was a thing of the past with 10% ethanol in fuels now. Strange.

[thom4782]

It could be lots of things. Only the codes will suggest the nature of the problem. BTW: secondary air system problems evidenced by a CEL often appear about 2 minutes after cold start up when a vacuum leak prevents the system from working properly.

[recycledsixtie]

I always carry a small container of gas line antifreeze in the trunk in case the gas line freezes. I have not had a gas line freeze for years but it is a pita if it happens if u don't have gas line antifreeze. Cheap insuranceThe colder it is the more chance of condensation especially if you don't fill up your gas tank regularly. Not sure what P manual says about gas line antifreeze but in an emergency I would use it.

[thstone]

My cheap code reader won't read any codes from my Boxster. None at all. When I connect it to the Boxster it says "Cannot connect" and won't display anything regardless of what I do. So I was forced to get a Durametric. Well worth it.

[particlewave]

I think it may have been a fuel issue? I was in KC a couple weeks ago, and had to stop for fuel. All that I could find was 91 octane.

I ran the tank almost empty, and refilled with 93 octane. After driving for about 10 miles, the check engine light shut itself off.

[Flavor 987S]

Originally Posted by particlewave

I think it may have been a fuel issue? I was in KC a couple weeks ago, and had to stop for fuel. All that I could find was 91 octane.

I ran the tank almost empty, and refilled with 93 octane. After driving for about 10 miles, the check engine light shut itself off.

You know nothing until you have a code. The code is still there, it's stored. The CEL just turned off becuase the fault cleared, possibly a loose/failing gas cap, for example.

[particlewave]

I still plan to get it checked, I just haven't had the chance yet. Today was the first day that I could get out, as we have about 3 inches of snow on the ground.

Side note: I got my daily driver fixed today as well
It was a bad fuel pump...

[shadrach74]

Originally Posted by particlewave

I think it may have been a fuel issue? I was in KC a couple weeks ago, and had to stop for fuel. All that I could find was 91 octane.

I ran the tank almost empty, and refilled with 93 octane. After driving for about 10 miles, the check engine light shut itself off.

There is absolutely no reason that 91 octane would cause a a CEL. What is more likely is that the gas cap vent was frozen at some point and the pressure in the tank would not equalize with ambient. When you removed the cap for fill up, that issue went away. For how log is anyone's guess. Read the code and you'll know where to start...

[shadrach74]

Originally Posted by Flavor 987S

Really, a frozen fuel line on the DD? I thought that was a thing of the past with 10% ethanol in fuels now. Strange.

Ethanol fuels are actually more likely to cause fuel line freezing issues because ethanol is hygroscopic. In non ethanol fuels any water ends up in the bottom of the tank which should be well below the fuel pick up (unless you really have a tremendous amount of water in the tank). Ethanol provides a a way for water to be held in suspension in the fuel and for that reason is able to get into the fuel lines.

[particlewave]

Originally Posted by shadrach74

There is absolutely no reason that 91 octane would cause a a CEL. What is more likely is that the gas cap vent was frozen at some point and the pressure in the tank would not equalize with ambient. When you removed the cap for fill up, that issue went away. For how log is anyone's guess. Read the code and you'll know where to start...

Thanks for the tip!

I'll have the codes read as soon as this snow is off the ground.