I have a base model 2021 Boxster. With less than 2,000 miles it has been back to the dealer twice because the PSM failure light comes on when approaching redline. Computer said misfires on cylinders 2 and 4 under 70% load at 6500 RPM. First time in they checked ignition and fuel components and thought the problem was resolved by replacing the spark plugs. The fault reappeared soon after receiving the Boxster back and it's now at the dealer again. After consultation with Porsche USA they tried replacing the injectors but that didn't resolve the problem. They are now in the process of removing the engine to inspect the valve train components. Anyone else out there with similar problem?
P.S. The car is a wonderful drive when it works.

My 2021 718 GTS 4.0 has the same problem. They are replacing the engine as well. It’s been in the shop for 60 days!

 

Very odd that you'd have the same problem because the base model 718 has the four cylinder engine but the GTS has the six cylinder.

 

Well not quite but here’s what happened to mine…

• Check engine light
• Running a little rough (hard to notice)
• Misfires on cyls 1,3,5

Mechanics switched sparkplugs and coils with cyls 2,4,6. Misfires continued w faults on 1,3,5. Dropped the engine and peeked inside and there was scoring throughout and oil where oil should never be. I’ll ask the mechanics on how the valves looked. So you’re right… may not be same…

 

There is a con rod issue on the GTS 4.0 which results in either an engine rebuild or replacement engine.
To the OP. Did you do the recommended engine break in period before you started to red line it?

 

They found a fix for my PSM failures. A new DME computer was sent from Germany. I took a month to get the coding right but once the new computer agreed to talk to the rest of the car the PSM failures, under load just short of redline on cylinders 2 and 4, ceased. Good luck with your GTS.