BartN (TX)

Yesterday we ran out to a friend's place about 40 miles away and ran the car at pretty high speeds for several miles. It ran perfectly. Even once we were back on surface streets it ran and idled as normal. At their place the car sat for about 4 hours before we started to leave. When I started it I immediately felt like it was running slightly rough. Like a cylinder was misfiring. After a few seconds the CEL came on. I cycled the car off and on a couple of times but had the same results. I drove it slowly for a few miles, pulled over and cycled it off and on and still same result. We drove it home at a very modest speed and parked it.

I have an 07 GT3 w/20K miles and up to date service, including plugs changed less than 2,000 miles ago.

Before taking it to the shop, do you guys have ideas for I can check for myself? I don't have a code reading tool.

RAudi Driver

Well start with the simple stuff. I know plugs changed so check the torque on them? Check the coil packs as it sounds like a bad coil.

Also just run down to the auto parts store and use their OBD tool for free.

Bxstr

Any chance you fueled it up just prior to this? Maybe a bad tank of gas is my thought, but I know probably unlikely. Raudi's suggestion could definitely be the cause as well.

I also don't have a code reader and these situations always make me think it's time for me to invest in a Durametric.

RAudi Driver

Quick note do not buy the Durametric enthusiast version. It's so limited, it's useless. Must get the Professional Version. I sold mine and would buy another one if the price was nice. However, I love my Launch diagnostic. It does everything I ask from it. $750 money well spent.

Wonderdan

Before you give yourself a heart attack on art of the possible check the simple codes like cat efficiency bank 1,2 w/any cheap code reader as Raudi said

Bxstr

Forgot about the Launch X431. Thanks for the reminder. Need to compare Durametric Professional vs Launch. I’d need to buy a new windows machine (something used for $200), so pricing between the two would be the same. I’ve used the Durametric in the past and it seems that it’s always been the go to Porsche scan tool (besides PIWIS), but I know some of the other tools like the Launch have more functionality and it’s across all cars.

Spyerx

Gotta pull codes.

RAudi Driver

GPC baby!

JB911

Get a PIWIS III- it's so affordable these days it's a waste of money buying Durametric, Launch and everything else-
JB

ABT_SLC

Dead coil or plug came loose on the coil.

Bxstr

Is there a plug and play PIWIS III solution? Like buy full setup and be able to plug in? For diagnostic reading, are you safe without a battery charger.

JB911

You need at least 40 amps to use PIWIS safely, this is according to the Porsche Service Manual. I use a Power Max 55 amp unit-
Then, if you already have a PC laptop, get the VAS 6154 VCI with firmware 1.6.6 on eBay or Aliexpress, and the PIWIS software
I got the 40.900.20 software since for 997s it's perfect-if you own a 2022 or 2023 car like a Macan you'd need another version. But this version covers quite a few of the newer cars. So around $250-$300 or more depending on software version, VCI around $68

There is a main dedicated PIWIS thread and a few others but if you want I'll recommend the best vendor, he installs it remotely on your laptop using TeamViewer-
JB

Bxstr

Thanks so much! Appreciate you explaining all of that so clearly. My main concern was the software causing issues with a module, even just during the reading process (not coding). But that seems unlikely especially with how many people are using PIWIS at this point.

RAudi Driver

Paging BartN! What's the status?

JB911

I have an AGM battery, full sized H8, and it failed after just 1.5 years. Replaced for free under warranty and it's made in Germany. Proof that batteries can fail-even though it's on my CTEK maintainer while the car isn't driving.
I described this nightmare and will post below. I confirmed something was wrong when I connected PIWIS, and even with the 55 amp power source the voltage indicator on Piwis itself only showed 13 volts. A cell was dying and replaced under warranty-but I almost got stuck and would have probably needed a tow. The high current steady power supply from Power Max is just over $120 if you shop, and overpriced at many suppliers. RV supplies are a good source.
Some people make their own, using used computer server power supply units for less than $20 on eBay. In either case, you need jumper cables, cut off at one end to attache to the power supply. Not doing so, whether using a Launch, Durametric or Auto etc is asking for trouble.

JB