Yes - that is a problem.

It's very likely that the previous owner had an AP and unmarried and sold the AP but was too lazy to replace the DP with an OEM piece. It's a common problem - selfish and lazy and describes the community to a Tee.

Don't drive the car until you can either tune for the DP or replace with an OEM piece.

 

^This for the engine issues which are pretty serious. If you are going to get a tune, add a 3 port-ebcs and Garrett TMIC as well for best results. Or stock dp if you want to avoid the hassle of tuning.

3rd gear isn't the best. If it's very hot or if you have ben driving for a very long time, the oil heats up and 3rd synchro feels bit crunchy. Double clutching and slow shifting smoothes it out. A user here @a5m figured out a gear oil that might be effective, shell spirax I think. I'm going to try that next. Pour a 75g tube of mos2 gear oil additive down the dipstick hole for minor immediate improvement.

 

Mirroring what was said above. All too common for these cars to be sold with modified parts and no tune because A) Seller removed AccessPort i.e. tune to sell separately for some extra cash or B) Dealer did the same. Get her tuned ASAP.

Yea I went down the rabbit hole for gear oils and settled on trying Shell Spirax, particularly S5 ATE (discussion here). Porsche uses it in their Aisin gearboxes, who manufacturers ours as well. Shell mainly sells it in bulk quantities and only overseas, so you either buy a $300-$400 pail or try and source $40-$50 liter bottles off eBay. Or you just buy it from Porsche, which is readily available in the States (Porsche Transmission Oil 75W-90 000-043-305-49). I actually bought mine overseas from Rose Passion, a popular Porsche parts store in France, for much cheaper landed than I was getting it here. Go figure.

Anyway I should update my thread on it but it's been great. Smooth as butter in -20°F or 100°F with no grinds. Never loses the feel with extended use. It'd be my recommendation anyway. Or you can try Mobilube PTX by Mobil. The other oil Porsche guys rave about besides Spirax. Again sold in bulk quantities but a couple Porsche tuning shops separate and sell it by the liter. Expensive.

 

Thanks for the response guys. Would getting a Cobb tune be sufficient and if so what tune do I run?

Also what damage could have been done driving it this way and what symptoms should I watch out for?

 

There are no cobb tuned available for the downpipe. You'll have to find a place willing to tune a vehicle with emissions modification and buy whatever tuning system they require.