High Altitude Issues 3.5 Eco Boost

[Ellison3]

I was able to get by the AutoZone today. This was the DTC they were able to provide me with:

PO151 - O2 Circuit Low Voltage Bank 2, Sensor 1

Secondary

P0299 - Turbo Under Boost

I’ve gotten that P0299 - Turbo Under Boost before. I live in Arizona, and get that code at times when it gets really hot out. Usually, my fans come on in O/D mode. Seems like their running non-stop (saw the thread about the cause). At some point if I’m in stop-and-go traffic the light may come on.

 

[B boyes]

I’ve gotten that P0299 - Turbo Under Boost before. I live in Arizona, and get that code at times when it gets really hot out. Usually, my fans come on in O/D mode. Seems like their running non-stop (saw the thread about the cause). At some point if I’m in stop-and-go traffic the light may come on.

I had been driving my truck for quite a while in the mountains. It is stop and go with a 20 mph speed limit in the city I was going thru.

 

[thatJeepguy]

P

I had been driving my truck for quite a while in the mountains. It is stop and go with a 20 mph speed limit in the city I was going thru.

Well at least you know now the lean condition was coming from exhaust leak as opposed to the failed sensor causing the afr to go lean. This is the better scenario.

 

[B boyes]

Do you guys think I could just JB Weld the small exhaust hole to put a bandaid on this issue till I can get into a service department?

 

[The Car Stereo Company]

Do you guys think I could just JB Weld the small exhaust hole to put a bandaid on this issue till I can get into a service department?

doubt it. probably too hot for it

 

[blwn]

Came down off the mountain after I started having issues. After some inspection I have a small hole in resonator and in my muffler. Hole is about a 1/8 -1/4 inch in diameter. I'm guessing from condensation from Oklahoma weather? Both holes are at the front of the components facing the motor. Both right on a weld seem.

The factory exhaust has holes to allow for condensation to drain and wouldn't cause these issues, especially since they're downstream of any O2 sensors. I'd troubleshoot why you're getting a low voltage code for that sensor.

 

[Stitch1618]

Hi all, my 2 cents: Driving mine in Switzerland and Italy up to 10000' never a glitch. always use minimum 95 Octane.

 

[FordTechOne]

P0299 sets when the actual TCBP value is less than the desired TCBP value 4 psi or more for 5 seconds, indicating an under boost condition.

TSB 16-0013 was released for this issue, which is caused by worn turbocharger wastegate actuators. At high elevation the air is less sense, so the PCM will command the wastegates closed to achieve the desired boost pressure. A worn wastegate actuator will prevent the wastegate from reaching the closed position, causing low boost pressure and an underboost DTC.

The TSB provides instructions on how to test the wastegate actuators by applying pressure with a hand pump. The TSB directs to replace the affected turbo for a wastegate issue, but the actuators are now available to service separately from the turbocharger assembly. Full race sells Borg Warner replacements for $119/pair.

 

[icecoldak]

Yep those small holes are Factory and allow condensation out just like BLWN stated!!!