So I have been chasing a problem for almost a year now ("HIS Truck" in signature). Truck runs OK, but at higher speeds (45-55) it becomes a dog at acceleration. Recently, the fuel mileage has gone from 15 mpg to something like 10 mpg. CEL only comes on sometimes.

In AE, I am getting two codes: P1209 (ICP Higher / Lower than Desired) and P1211 (ICP Peak Delta Test Fault)

Also in AE: I checked the following in Live Data Meter KOEO
EBP Volts: 0.88
EBP: 14.32 psi
Barometric Pressure - Volts: 4.51 (this was highlighted in RED, temp outside at time of measurement 54 degrees, and I am less than 100 ft above sea level)
Manifold Absolute Pressure: 14.1

FWIW: My ICP and IPR are both new, including the ICP pigtail. MAP hose was replaced last month due to being hard and cracked up. I have no EBPV as it has been gutted / delete pedestal, etc. HPOP is a TE and has maybe 30k on it. Turbo was rebuilt about 20k ago.

Just curious if the MAP could cause the P1209 and P1211 errors, and wondering if the Barometric being red was an indicator of some issue as I was reading you wanted EBP / BARO / and MANIFOLD all close together. I will be very frustrated if the IPR somehow is faulty, especially since I replaced it last year with an OEM IPR (instead of rebuilding the one that was in there, which I did when I upgraded the HPOP).

 

Map wont effect HPOP codes. the map does Injector PW and boost/waste gate functions. I would look into oil passing the injectors, have you replaced them? measure the pressure of the HPOP and make sure it's were it needs to be.

 

Check MAP while driving and getting on it a bit with AE. If it stays at 14.1 then either you have no boost, something somewhere in the engine to MAP is clogged or the MAP is bad. MAP sensors seldom fails. Lack of proper MAP boost will usually throw a code though.

ICP codes are usually due to PCM trying to control pressure via the IPR but can't within programming specs. With AE monitor ICP pressure and IPR% while driving, that will tell the story, at least get a good starting point.

Often overlooked is fuel pressure. AE can't help you there but before doing anything radical at least check the pressure with an external gauge. Low fuel pressure will cause all kinds of power problems especially at higher speeds as the injectors require more fuel.

 

I have seen low fuel pressure throw a 1211 code in my truck.

 

MAP has no effect on FIPW, ICP, or IPR. MAP is air, all that other stuff is oil - to amp up fueling. Boost is a result of fueling, not the other way around.

With all that stuff on the truck, I saw no mention of a chip or tune. Cody test (I'm on a roll).

 

Ok, that what I thought but figured the code could be thrown by both possibly.

As for fuel pressure, in the past year I have put a pressure gauge on both pretty and post fuel filter and the numbers were perfect. However, I have no way of measuring the fuel pressure under load since it is an under hood gauge and I don't want to remove hood and drive down freeway like that. Lol In cabin fuel gauges are quite expensive. But I am wondering if maybe the FPR could be sticking a little bit so maybe a FPR rebuild is in order.

Tugly, there are no tunes or chip on HIS truck, and hasn't been in years. Hasn't been an issue. As far a the Cody test, was hoping not have to get that invasive...I rarely have all day to do under the valve covers work. But, it is my understanding that if I had a leaky injector oring I would have starting issues most likely, and I don't.

Maybe I should build a boost leak detector and go that route.

 

You don't have to pop the VCs to do the Cody test, but you need a quiet environment to hear any leaks.