So after months of waiting I finally got to drive my 2002 911tt tip. I took it to work today, about 50 miles round trip, and on the way home I got a CEL light. I didn't beat on it, but did a couple of runs on the highway hitting 0.8 BAR and even seeing a spike to 1.1. I have no clue if my car is modified in any way as I got it from an auction, how can I tell to make sure?

So on the way home, driving about 65, without even getting into boost, I get a CEL light. I got home, grabbed my durametric and pulled these codes, all of them from today as I cleared everything last week:

P0234- Boost pressure Deviation - exeeds limit value

P0172- Porsche Fault code 360 - Oxygen sensing adaptation

P0175- POrsche Fault COde 361 - Oxygen sensing adaptation


What could cause this? Any ideas?

I also managed to scrape my carbon fiber lip- grrrr

 

In case you don't have the OBDII manual:
P0234 as a possibility first check for leakage at pressure hose from frequency valve to the bypass flap. Or frequency valve at fault. Vacuum modulators for bypass valve leaking. Bypass valve incorrectly adjusted.
P0172 and P0175: incorrect signal from MAF sensor, fuel pressure too high or fuel injector leaking or EVAP canister purge valve open.

These problem seems not to be related. except of course for 172 and 175

 

I had these codes when my headers cracked....

 

You might be onto something as my car was from an auction and was lightly hit from the back......

Dang, now I'm gonna have to upgrade the headers and get an exhaust....

 

Let me know what you find out...I had the same codes pop up recently.

 

Has to do with exhaust, I think it may be the O2 sensor positioning. Keep us posted.

 

Theres a set of used headers on ebay for $50 bucks....

I'm pretty sure its the headers. Unlikely its the exhaust

 

What's the reasoning for the boost deviation code if it's an O2 sensor or cracked header issues?

 

I think being that the header is cracked.. the turbo cannot flow properly.

To be honest, i don't know. I'm just telling the OP i had the same exact problem, and how i fixed it.

 

Not sure about the boost deviation, could be many things: hoses, DV's, headers, etc. I've seen those codes before on loose exhaust systems.

 

I took it for another spin today(the codes were cleared yesterda). My buddy mechanic suggested that the wastegates have a tendency to stick if the car is not driven for a perid of time. Well I beat on it today on my way back from work after having the tire fixed and everything was perfect, no CEL. The top boost was .7 .8 3-5th gear (tip) so that would be about right since before I seens spikes of 1.1 which might've caused the overboost and the code. I'll report what happens in the days to come.

 

Drove the car for 1 day with no problems. On day the CEL light and the same codes are back. I gotta get it on the jack stands and look at the headers.

 

So, as I posted in my other WG thread, I did put the car on jackstands and inspected it. The headers look perfect but one of the wastegates was stuck shut. I got it loose/unstuck and drove it fine for weeks. Today I get a CEL light pull the codes and get:

P0172- Porsche Fault code 360 - Oxygen sensing adaptation

P0175- POrsche Fault COde 361 - Oxygen sensing adaptation

But the boost pressure deviation is gone.

Also, I remember that before I got the WG unstuck I was usually pulling .7-.8 Boost with spikes of 1.1. Now all I'm seeing is 0.5-0.6bar. I believe my car is stock. Any ideas what might be causing these?

 

Maybe the DV's ??..someone can chime in. If you are looking for a local shop , i highly recommend CPT in Melrose Park.