CEL above 75mph
 

I have a 2003 base with 114,000 miles. When I get above 75 MPH either running it up through the gears in 3rd or accelerating in 5th I get a CEL and codes for a misfire on bank 2. It does not happen even if I run up to 7k in 1st. Only when I get above 75 and has cleared it self 2 of the 3 times it has occurred. I have new coil packs coming since they are all original. Anyone else seen this?

If you haven't changed the plugs in awhile, I'd do those too.

6 Pieces Bosch FGR6KQE 4 Prong Spark Plug Porsche 911 Boxster Cayenne 8CYL | eBay

And while you are in there,
1.check the coils for cracks.
2. the spark plug tubes for oil leaks

2003 Boxsters don't use spark plug tubes.

I beg to differ. I have just rebuilt my M96,21 and each spark plug recess has a tube and two seals.
Pelican Technical Article: Replacing Boxster Spark Plugs and Coils - 986 / 987
see fig 3.
Part # is : 996-105-325-52
Pelican list them for the '03 & '04 Boxster
'05 Boxster ,different story

You didn't rebuild a 2003 engine then and Pelican is wrong. I bought them and went to install them and noticed the car didn't show any oil residual around the plug holes and I couldn't see them either. I came back in to check Pedro's DIY, low and behold.

Change Spark Plugs & Tubes

http://986forum.com/forums/performance-technical-chat/55780-spark-plug-tubes.html#post435477


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When I bought the car it had an Aos failure so I changed the plugs after I did the aos figuring they were fouled. The car had several other problems so I did not replace the coil packs at that time as I was not sure if any of the problems were terminal. Now 13,000 more or less trouble free miles later this is the first problem I've had since getting it back on the road.

Hopefully they don't look like mine did.

http://986forum.com/forums/general-discussions/55792-bad.html

I got lucky and got a set of 6 perfect used coils shipped to me for $65 from one of the most reputable used Porsche parts sellers on eBay.

SIDE NOTE: Even with the coils in the awful state they where in, I never got a CEL for misfires.


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Kram
Thanks for the correction. Someone better tell Pelican about their error.
You are correct mine is a 2001 S.

I just sent Pelican a ticket on this. Been meaning to do it.

My coils came in the mail today hope to get them in this weekend. Went over 85 a couple times on the commute to work (it's Friday)!!! No CEL was even raining. Not sure what is causing the problem. I'll just have to keep driving fast and buying parts for my Porsche :-)

Could it not be related to the rear spoiler that deploys at exactly the same speed?

I thought the same thing when I read the title of the post, but the codes are for misfires.

Pelican replied back on the spark plug tube ticket I sent.

I much like Pelican am going to need a few more days to get my coils in. Had to replace the water pump and timing belt in my son's car this past weekend. Back and legs were sore by the time we got that done. A Cadillac is like a Porsche in that the designers work really hard to make as many things as possible overlap and have to be removed in layers.

I know the feeling after putting in my upgrade to the intake system. My back said no more please!

Luckily you get to the coils from the bottom. Just jack the car up and scoot under it and replace them. Your arms will feel this one though lol.

So one update my title should read CEL Above 85 mph. I was letting off and not looking at the speed the first few times this happened.

I installed the coils today took it for a run engine performed better smoother idle. CEL still returns around 85 MPH. Checked the codes again still getting P1325 Porsche fault code 901 inlet camshaft bank 2, P0304 Porsche fault code 511 misfire cylinder 4, and P0300 Porsche fault code 507 misfire detection (total).

Still only happens at speed can run to high RPM in fist and second without happening. Trying to decide what to do next.

Hey, your state's highest speed limit is 70 MPH. What are you doing driving 85 MPH?

I think you should be a hypocrite like coreseller and a couple others, go into the following thread and give that KRAM36 guy a hard time, but please ignore he put nobody in harms way, but himself.

http://986forum.com/forums/general-discussions/56496-boogity-boogity-boogity-whats-fastest-you-have-had-you-boxster.html

I was talking with a mechanic buddy he mentioned that it could be a lean fuel condition causing the CEL at speed. Other than injectors is there some other likely cause of a lean condition?

Gas Cap

http://986forum.com/forums/general-discussions/56609-p0300-only-code.html