I wanted to flash my 996 C2 (MY2000, eGas), once I had finished some small upgrades (Bypass, gt3 throttle body, IPD plenum & BMC air filter) and was suggested not to.

The dyno chart bellow, showed ~25 hp were missing and second half of the chart has little less torque than expected. It didn't look a big deal to me:

[IMG][/IMG]

Anyway the tuner found too lean mixture at the higher end (above 6000 rpm) so he recommended me to find out the reason before going any further. Since he is not a Porsche specialist he could not help much and thought about a weak fuel pump...

Anyway I'm not that sure about it. As I have a durametric cable I've done a couple logs and here is what I got on a 3th gear WOT launch:

1-RPM
2-Mass air flow (MAF)
3-Adaption, range 2 (FRA), bank 1
4-Adaption, range 1 (RKAT), bank 1
5-O2 sensor voltage ahead of cat. conv., bank 1
6-Adaption, range 2 (FRA), bank 2
7-Adaption, range 1 (RKAT), bank 2
8-O2 sensor voltage ahead of cat. conv., bank 2

1 2 3 4 5 6 7 8
1.681 160 1,02 -0,19 0,84 1 -0,52 0,87
1.928 188 1,02 -0,19 0,88 1 -0,52 0,88
2.176 221 1,02 -0,19 0,86 1 -0,52 0,87
2.418 237 1,02 -0,19 0,88 1 -0,52 0,88
2.673 244 1 -0,19 0,88 1 -0,52 0,89
2.921 295 1 -0,19 0,88 1 -0,52 0,87
3.156 323 1 -0,19 0,87 1 -0,52 0,86
3.400 342 1 -0,19 0,88 1 -0,52 0,88
3.679 390 1 -0,19 0,87 1 -0,52 0,87
3.985 437 1 -0,19 0,87 1 -0,52 0,88
4.253 468 1 -0,19 0,87 1 -0,52 0,87
4.539 516 1 -0,19 0,87 1 -0,52 0,86
4.816 561 1 -0,19 0,86 1 -0,52 0,86
5.104 589 1 -0,19 0,85 1 -0,52 0,85
5.424 624 1 -0,19 0,84 1 -0,52 0,84
5.697 667 1 -0,19 0,84 1 -0,52 0,83
5.988 695 1 -0,19 0,83 1 -0,52 0,83
6.286 680 1 -0,19 0,81 1 -0,52 0,81
6.565 704 1 -0,19 0,81 1 -0,52 0,76
6.857 764 1 -0,19 0,83 1 -0,52 0,82
7.056 784 1 -0,19 0,85 1 -0,52 0,83
7.306 643 1 -0,19 0,84 1 -0,52 0,81


Cleaned MAF and checked for leakages already.

I'm pretty lost here.... Need a new MAF, O2 sensors, check hidden leakages???

Any suggestions will be wellcome.

Thanks