alexjc4

11-12 normal for a turbo, but way rich for a na, especially a 964 which will usually be 13-13.5 on a WOT run.

You are right that 14.7 is for idle and cruise really. Though I'm told some really modern stuff now runs that lean at WOT, which is bonkers, but they have found ways to do it for the sake of emissions and economy.

-nick

That's very interesting! I haven't kept up on the latest modern tuning biz. Not applicable to our 964's, but neat nonetheless.

The chip is tuned to be hitting ~13.1. So something is assuredly wrong.

Next on the list is to figure out a way to see if the intake resonator flap is opening correctly at rpm. GoPro ziptied in the engine bay perhaps? Vacuum to it checks out, as does the electric solenoid response. Though no way of knowing if the motronic is actually telling it to open at the right time other than seeing it in action. Not sure if the mix would go rich if it doesn't open, but it's something to test and rule out.

Duck

I am by far no expert, but does't the DME ignore the O2 sensor and also the AFM would be maxed at WOT. So is the map for WOT and estimated map based on a specific setup and therefore is not going to adjust based on sensors. If the map is set up correctly, then it would be some restriction in air flow?

Lorenfb

Totally correct! One of the few that's knowledgeable about the 964 DME ECM
functionality which includes so-called "performance chip" makers on this issue.