Hello Rennlisters,

i have a dilema on a 2001 Porsche 996 turbo, running GT660 EVOMS tune with 1050x injectors, K16 billet turbos, Hitachi Mass Air, Catless Exhaust, intake tubes off Turbos.

Car has been pulling codes P2135 and P0121, thought it was Pedal Potentiometer, so had it replaced. Drove home and it still comes back. Not that this is related, but I am also getting codes P0051 and P0151 as well regarding o2 sensor area. Pedal will go into limp mode and open 30 pct on wide open throttle.

Has anyone experienced this, iif so how did you resolve it?

Thanks,

Steve

Noted.. thanks just realized this is not turbo

Unplug maf and drive it. If it’s running better install a new oem Bosch maf.

It is using a hitachi mass airflow sensor, almost bulletproof

Maf’s are a normal wear item and when faulty can cause all kinds of issues even unrelated. I’d narrow it down by throttle body, maf, and battery etc. All are free to check and will help eliminate having to throw parts at the problem.

Thanks for your response. So far I have cleaned throttle body and set adaptation, cleaned maf... and replaced pedal potentiometer. I am curious if the code is related to the o2 sensor code p0050 and p0155 telling me to replace it. If you clear the codes, immediately o2 code comes back, then after some driving check engine light for 02 comes on then lastly
limp mode code p2135 and p0121 show.

Steve

unhook battery for 20-30 min then rehook and try again. Go through this thread similar issues

https://www.pistonheads.com/gassing/...f=48&t=1239253

Thanks Atrox. I did replace pedal potentiometer, and code returns. I am leaning toward bad gas pedal iteself or o2 sensor causing limp mode triggering code
simultaneously. What do you think?

Well found the problem, for those of you who experience a p0050 and p0155 02 code and p2135 and p0121 be sure to inspect o2 itself to find harness was shorting out causing limp mode on throttle.

Hope this helps others with the limp mode.