I just got everything buttoned up with the car after doing some winter maintenance on it.

- Replaced yellowed coolant overflow tank and new cap
- Replaced fuel filter
- Replaced throttle body gasket
- Fixed boost leak post driver side IC

I fired up the car and it immediately threw a code

P0238
Porsche fault code 353 - Pressure sensor boost pressure exceeds limit value

I searched but really didnt find this code so I wanted to see member thoughts on this while I tried to track it down. The first thing I am thinking is that the MAF might have gotten a little dusty/dirty while everything was out. Going to clean it and see if that helps first.

Any other ideas?

 

I started getting that when the T-line off the N75 going to the waste gates broke. It likely means your waste gates aren't actuating properly cause you to over run the boost threshold holds. If I'm right be careful because you can cause serious heat issues in the engine and a lot of damage potentially.

 

I just did a boost leak test and there is a very very slight leak at the N75. The wastegates seem to be functioning properly doing a visual inspection while pressurizing the system. Going to pull it apart and replace the N75 and tighten down all of the hoses.

 

The boost sensor is on top of the y pipe near the throttle body. Did you reconnect the wiring harness to it when you reassembled everything?

 

Yep, double checked everything. Since post

- Cleaned MAF (just in case)
- Checked all connections (all plugged in)
- Did a boost leak test (very slight leak at N75)

Ordered a new N75 and am going to zip tie all lines when I redo it.

 

That code is your map sensor on the y pipe. If the n75 didn't fixed it then you need to replace the map sensor.

 

Thanks man. Will order that as well. Dont mind spending the 20-30 on sensors as they are cheap compared to piece of mind.

 

For a Map to be toast is very difficult. I think you might have forgot to put the wire on or clicked it in enough. You can clean it also. Did u out a new gasket on?

 

I will check it in a bit. The plug seems to be on it tightly but will check again. Didnt touch the sensor when I put on the new TB gasket.

 

feeling a bit dumb about even mentioning this though but i will add this given that 996550hp already has mentioned this possibility ..i just wont feel as stupid lol

i was doing simple tb reset since i was taking out this sprint booster ( anyone want one? going cheeap lol )...

and what happened was it was about 32 degrees outside and i could barely click it together to release the module from its housing ( or hear/feel? it connecting ) connector ( the maf ..not n75..) as you know it "clicks" upon re-insertion into the connector but my hands we so fracking cold i could barely push the thing ( the two sides! ) together! let alone HEAR it "click" as it does upon re-installation!

point is it took my 3 tries with 3 same abs/psm MAF related codes before i was able to properly re-insert with the audible "CLICK" the MAF into the housing. i'm NOT saying this is your issue, but i have never had to reinsert the maf 3 times before. i blame the weather but it was NOT fully "clicked"! and that was causing me the grief that a sunny day wouldn'tve

there.. i still feel stupid lol