Code p0238 but low boost
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Code p0238 but low boost
I have a E99 with a ts chip, 4" turbo back straight pipe, and I just installed an edge insight cts. Under hard accel. I'm getting the p0238 code but the insight says I'm only building 14 pounds of boost.
According to my insight, map psi is 14 at idle and 28 under hard accel. Ebp is 0 at idle and I saw it get to 34 under hard accel. These numbers look ok? Also pulled the red line off the waste gate and plugged it. Still only built 14 psi on my insight. Thanks for any help
According to my insight, map psi is 14 at idle and 28 under hard accel. Ebp is 0 at idle and I saw it get to 34 under hard accel. These numbers look ok? Also pulled the red line off the waste gate and plugged it. Still only built 14 psi on my insight. Thanks for any help
Postmaster
Joined: Jun 2014
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From: Oakhust NJ Jersey Shore
14 PSI boost on a stock turbo sounds about right, your map starting at 14 adding 14 which would equal 28 is over boost hence the code, plug the wastegate back in it doesnt really make a difference, I to believe the MAP is out of calibration, The EBV is not stuck on, or it doesn't do this only when cold does it? The EBP sounds high, straight 4 inch exhaust, something is out of whack, Call edge see what they recommend 
Hotshot
Joined: Jan 2011
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From: Puget Sound
Your EBP is set to "gauge" pressure, not absolute. Your MAP is absolute, you may want to select Boost.
Set everything to absolute or gauge, but not a mix - then take a reading at KOEO (Key On Engine Off), they should match.
34 PSI EBP gauge with 14 PSI boost is just so wrong - that could be a big boost leak or a stuck EBPV. Once your PIDs are set to the same reading style, go for a casual drive on the highway and see what your EBP gauge/boost or EBP absolute/MAP is. You should get about 3-5 PSI with each on the flat with no wind - and the EBP will drift to about 1 PSI above the MAP/boost.
Make sure you don't do any WOT tests with an engine less than full operating temp (above 150 degrees EOT).
I wish you could log data.
Set everything to absolute or gauge, but not a mix - then take a reading at KOEO (Key On Engine Off), they should match.
34 PSI EBP gauge with 14 PSI boost is just so wrong - that could be a big boost leak or a stuck EBPV. Once your PIDs are set to the same reading style, go for a casual drive on the highway and see what your EBP gauge/boost or EBP absolute/MAP is. You should get about 3-5 PSI with each on the flat with no wind - and the EBP will drift to about 1 PSI above the MAP/boost.
Make sure you don't do any WOT tests with an engine less than full operating temp (above 150 degrees EOT).
I wish you could log data.
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I will check the settings out. I checked the up pipes for leaks. Didn't see any. Checked clamps on intercooler boots. It builds boost nice untill 14 psi an then just dead heads at 14
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Hotshot
Joined: Jan 2011
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From: Puget Sound
That sounds more like a bad MAP sensor. Maybe you pulled a Tugly - exceeded the MAP limit, set a code, then the MAP started lying to you. I had to install a boost fooler on the MAP line and an external boost gauge to work around the problem.
If this is the case, you may ultimately want to back off the wastegate, once you find out what your true WOT boost is. I've been told 40 PSI is the truck limit - when new. Above that, the valves may float on a stock truck - bad juju.
If this is the case, you may ultimately want to back off the wastegate, once you find out what your true WOT boost is. I've been told 40 PSI is the truck limit - when new. Above that, the valves may float on a stock truck - bad juju.
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My wife has the truck so havnt had time to check anything else out. I was also thinking bad map sensor since the code that gets tripped is for an electrical problem. The regulator is just for allowing a certain amount of boost pressure to reach the map sensor?
Hotshot
Joined: Jan 2011
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From: Puget Sound
This is my boost fooler [LINK]:
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Cargo Master
Joined: Aug 2009
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From: Glendive, MT
Click the link Rich gave you and do a little reading. It will tell you where to set the regulator and at what boost level your truck will start to defuel. I have that one as well.
Hotshot
Joined: Jan 2011
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From: Puget Sound
The unit from Clay (Riffraff) needs no adjustment - it's calibrated for our truck. Install and drive. How cool is that?
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I found a new map sensor at work so I put the new map and a new hose on. No change. 14 psi and same code. I saw I could monitor waste gate duty cycle percent. It was 98.8% all the time. Idle to floored.... What's that mean?