I'm hoping someone might have some kind of experience with this. My car is going into limp mode with no codes/CEL. When checking, the only thing that pops up is P1249. The weird thing is that the error seems to pop up only when the car is cold and not fully warmed up. I'll keep the revs low, with low throttle below 3K but error will still happen. However, after car is fully warmed up, I can clear the code and do multiple full throttle runs up and down the freeway on full boost with no issue. Car is on a OTS ACN91 Cobb Tune. When working correctly, boost will go up to 1 bar and spike 1.1 sometimes. With P1249, it is only hitting 0.5bar. This morning, I also tried keeping it out of boost until fully warmed up. With that, no error and no issues with full throttle and full boost when fully warmed up. I just had a full engine out service with hoses replaced everywhere so I don't think there are any leaks especially since I can't replicate the code when it is fully warmed up. Error also occurs if I start the car middle of the day when it's been parked for a while, also not fully warmed up. I'll do a pressure test when I have some time to get it up on a rack but wondering if this has happened to anyone before?

 

Likely a boost or vacuum leak. I would run a comprehensive boost leak test per multiple markski posts or others on here. Attached is a manual page on the issue ….

P1239 manual

 

Thanks for the response. I did run a boost leak check and found one of the four main boost hoses wasn't completely locked in.

 

That will do it.