Need help with LSA tune / P0151 code on CTS-V

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04-25-2019
TriTexan

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Need help with LSA tune / P0151 code on CTS-V

I have a highly modified LSA on a 2014 CTS-V with a custom tune. Tuner no longer around and the car runs fine but it's time for inspection and I'm getting a P0151 code quite frequently. I've replaced the O2 sensors and done my best and I am fairly sure the sensors are working ok. This code points to a malfunction in the sensors but in my case I suspect the car is running WAY lean for a short period - see below.

I have my tune to post and will get logs shortly. The issue occurs in a pretty specific scenario - it happens when the car is just getting warmed up - not cold, but after 2-3 miles of driving, and only when I lift off the throttle and the car goes to idle in gear (auto trans) in the 30-65mph range (so not slow speeds only). I have a wideband and at least confirmed the car isn't running lean under any sort of power situation - so I'm not scared to drive it like this as it's only briefly lean on coast and then only in short bursts just after warming up, then fine after that.

So this is some kind of coast-down, DFCO, or idle airflow issue of some kind. Unfortunately I understand some of the concepts but have pretty much zero tuning experience. I have HPT to make remote tuning support (like this!) easier, but that's about it. I leave changing anything to the experts (like you guys).

The mods are extensive - Tony Mamo ported TFS 255 heads, LT headers, custom cam (medium duration but ~.600 lift), overdriven blower, lots of cooling mods obv, FIC1000 injectors, 102mm TB, large intake, full custom exhaust, and so on and so on...car does have cats and all pre and post-cat O2 sensors, all connected (plus the wideband).

Would greatly appreciate any advice or recommendations and will do my best to capture a log shortly.
04-25-2019
PGA2B

Turn off DFCO. Change the enable ect to something you can't reach. Mine is at 280. Some max it all out.
04-25-2019
TriTexan

Quote:

Originally Posted by PGA2B

Turn off DFCO. Change the enable ect to something you can't reach. Mine is at 280. Some max it all out.

Thought I had done so but quite possible I did it wrong. I didn't try using ECT...will give that a shot.
04-25-2019
PGA2B

Your DFCO is all stock
04-26-2019
TriTexan

Quote:

Originally Posted by PGA2B

Your DFCO is all stock

Doh...yeah, on this file. I think I had tried this before with a temporary tune and put it back to the baseline. Again - I think I tried it using the rpm enable/disable. But I've maxed out all values today. Will see how it goes.

One other question: for OBD2 testing there is a "ready" condition. Can I see the testing readiness status in HPT somewhere so I know if the MIL/CEL has been off long enough to get it tested before going in?
04-26-2019
PGA2B

In the scanner under Vehicle>Diagnostics & Info
05-08-2019
rodmankn3

Hey TriTexan, glad to hear from you around here. I'm still the owner of your old wagon.

PGA2B - I have been hearing about this "DFCO" all the time, but I look at the tab that has DFCO in the editor and there is nothing labeled DFCO. What/ where is DFCO? still learning, don't shoot me...;)
05-08-2019
PGA2B

Engine>Fuel>Cutoff, DFCO

Deceleration Fuel Cutoff
05-08-2019
rodmankn3

ok, thanks. I only have the enabled/ disabled options for spark, Fuel and ETC. Lamp RPM and Cutoff RPM.
05-09-2019
PGA2B

DFCO is not an enable or disable. There are settings you change the table.
06-21-2019
TriTexan

Well after driving the car for quite some time, there is no longer a CEL popping up - car drives fine, no issues. But in HP Scanner, I'm still seeing "Incomplete" in the readiness tests for O2 sensor and Catalyst, and showing an O2 sensor permament code for rich-to-lean. Will grab screenshot for exact text later.

So clearly something on the diagnostics self-test isn't clearing so the car can be inspected, but it's also not throwing any codes anymore. Thoughts/ideas?
06-21-2019
TriTexan

Glad my gray wagon is still out there and doing well! Hope you are treating her right!
06-21-2019
TriTexan

Quote:

Originally Posted by rodmankn3

Hey TriTexan, glad to hear from you around here. I'm still the owner of your old wagon.

PGA2B - I have been hearing about this "DFCO" all the time, but I look at the tab that has DFCO in the editor and there is nothing labeled DFCO. What/ where is DFCO? still learning, don't shoot me...;)

Glad my gray wagon is still out there and doing well! Hope you are treating her right!
06-22-2019
5ft24

Quote:

Originally Posted by TriTexan

Well after driving the car for quite some time, there is no longer a CEL popping up - car drives fine, no issues. But in HP Scanner, I'm still seeing "Incomplete" in the readiness tests for O2 sensor and Catalyst, and showing an O2 sensor permament code for rich-to-lean. Will grab screenshot for exact text later.

So clearly something on the diagnostics self-test isn't clearing so the car can be inspected, but it's also not throwing any codes anymore. Thoughts/ideas?

From what I understand, Permanent codes can't be manually cleared via scanner. they have to not have the error pop up for a number of drive cycles before they clear themselves.
What number is the code?
06-25-2019
TriTexan

1 Attachment(s)

So here's what the scanner shows. What's interesting is this same car and tune has passed emissions no problem the last few years. Something has maybe gotten out of whack (prob because a lot of the adaptive characteristics are not enabled in my and many other custom tunes?). I'm curious to know what might be causing this to have worked fine before and not now - the tune may need a tweak?

Attachment 90990
06-25-2019
5ft24

you have 2 incomplete emissions tests, O2 and Catalyst.
No emissions test will pass with those codes set
06-26-2019
TriTexan

Captured a freeze frame...

Freeze Frame: 0
DTC: P015A - O2 Sensor Delayed Response - Rich to Lean (Bank 1 Sensor 1)
Fuel System Status: 04 04
Calculated Engine Load: 20.3921568627451 %
Engine Coolant Temp: 90 ?C
Short Term Fuel Trim Bank 1: 0 %
Long Term Fuel Trim Bank 1: 0 %
Short Term Fuel Trim Bank 2: 0 %
Long Term Fuel Trim Bank 2: 0 %
Fuel Pressure: 294.00030666584 kPa
Intake Manifold Absolute Pressure: 35 kPa
Engine RPM: 1481 rpm
Vehicle Speed: 91 km/h
Timing Advance: 0 ?
Intake Air Temp: 43 ?C
Mass Airflow: 16 g/s
Throttle Position: 20.3921568627451 %
O2 Voltage B1S1: 477.5 mV
O2 Voltage B1S2: 844.98046875 mV
O2 Voltage B2S1: 712.5 mV
O2 Voltage B2S2: 839.98046875 mV
Run Time Since Engine Start: 377 s
Commanded EVAP Purge: 0 %
Fuel Level Input: 40.3921568627451 %
Warmups Since MIL Clear: 2
Distance Since MIL Clear: 60 km
EVAP System Vapor Pressure: 16383 kPa
Barometric Pressure: 101 kPa
Catalyst Temp B1S1: 754 ?C
Catalyst Temp B2S1: 751 ?C
Control Module Voltage: 14 V
Absolute Load: 18.4313725490196 %
Commanded EQ Ratio: 1
Relative Throttle Position: 8.62745098039216 %
Ambient Air Temp: 32 ?C
Absolute Throttle Position B: 20.3921568627451 %
Accelerator Position D: 20 %
Accelerator Position E: 9.41176470588235 %
Commanded Throttle Actuator: 11.7647058823529 %
60: 01 00 00 00
06-26-2019
TriTexan

Quote:

Originally Posted by 5ft24

you have 2 incomplete emissions tests, O2 and Catalyst.
No emissions test will pass with those codes set

Yeah - I understand that. What I'm unsure of is why I have no CEL, been driving the car extensively under a wide variety of conditions (cold start, accel, cruise, multiple gears and speeds, wide range of coolant temps, rpms, etc) but these readiness checks are not clearing. That's what I am unsure how to clear.

I can zap the DTC's and reset everything, no problem. But if I'm getting no CEL anymore, I'm wondering why these systems are never showing ready for testing?
06-26-2019
sevinn

I believe the catalyst and post o2 tests have to be enabled for the readiness monitors to clear.
06-28-2019
JBZ

TriTex...whats up brotha, is your car running in constant open loop? For some reason it seems to be that your O2s may not switching. can you post up a log file? looking at your tune there is no reason to think that is the case but knowing your tuner that you used i wouldn't put anything past him. off subject but in my opinion you should enable LTFTs. it is disabled in your tune file you attached with your OP. I have ARH longtubes and IIRC you do as well. i have some better values to give you in quite a bit of the tables in the oxygen sensors that i tuned in for ARH headers and that may generate better swinging in your O2s that may be able to help with the P015A/C codes (not switching).