lean area around 2500ish rpms-2014 ctsv

[L1FTD]

So did you max out all of your mis-fire tables and it fixed the lean spot initially? I thought that's what you mentioned before. I've never messed with any of the mis-fire tables before

I think first try at misfire I just set the test RPM Enable up to 8000rpm. I?ll try and find the the log. I?m not sure what else played into the log, but it was rich everywhere and no spikes. I was only looking for the damn WOT ones again too.

I?ve tried enable rpm 8000 + stock tables, enable rpm 8000 + tables maxed, enable rpm stock + tables zeroed.

I haven?t tried enable rpm 8000 + tables zeroed, enable rpm stock + tables maxed.

I get higher misfire counts in the scanner, going through 2600rpm WOT.

Hasn?t changed much for me, maybe the last two combos I haven?t done will be the miracle

[L1FTD]

From what I've been experiencing we need high pressure during part throttle conditions and lower pressure during wot conditions...lol

Yeah haha completely backwards.

You could probably set the flow tables to switch from low@idle, high@part-throttle, low@WOT low rpm, high above 3000rpm.

Would be tricky to do, and never perfect. Way too many variables for fuel demand. Have it good in summer, then all the switch points change in winter etc.

[JayRolla]

Nope, I have mine installed and ran with and without them turned on and still have it.

Do you have cats installed so it doesnt throw codes when activated?

[GHuggins]

If y'all are sure it's situated with the rear O2's, have you tried reactivating the test for them when they were reinstalled? There is another setting for how many post O2's the vehicle is equipped with. Some calibrations have it, but most don't. I've never had any luck with changing the post O2 counter to 0. It always seemed to make the front O2's get randomly stuck for some reason. Might have something to do with how the front O2's test operate and requires other settings to be changed? Really don't know on that one.

[PGA2B]

I do have Cats but it threw a code with them. So I shut them off and cleared the permanent P0420 & P0430 codes.

[sgod1100]

If y'all are sure it's situated with the rear O2's, have you tried reactivating the test for them when they were reinstalled? There is another setting for how many post O2's the vehicle is equipped with. Some calibrations have it, but most don't. I've never had any luck with changing the post O2 counter to 0. It always seemed to make the front O2's get randomly stuck for some reason. Might have something to do with how the front O2's test operate and requires other settings to be changed? Really don't know on that one.

If we have it where would that setting be? (number of post 02s the vehicle is equipped with)

[GHuggins]

It was only ever put into a few calibrations before they started removing things back out. It was under the O2 settings in the main calibrations.

O2's.jpg

[sgod1100]

It was only ever put into a few calibrations before they started removing things back out. It was under the O2 settings in the main calibrations.

O2's.jpg

Gotcha, thanks. Yeah, doesn't have that in the cal

[sgod1100]

so....anyone want to put cats back on their car and re-enabling everything to see if it corrects the problem??? lol

[L1FTD]

It was only ever put into a few calibrations before they started removing things back out. It was under the O2 settings in the main calibrations.

O2's.jpg

Been doing some more research, along the same lines of inquiry as sgod1100 it seems

There's a mountain of tests the ECM will do at will. Looking through these diagnostic pages, I struggle to find any tests that should still be applied when in open loop.

Quite a few o2 tests (stuck rich/lean in particular) seem to enable above 1100rpm and then disable above 2650rpm. Only problem is they all appear to enable in closed loop, and when I experience the lean spots I wouldn't be meeting the criteria to keep these tests enabled. Even the commanded EQ must be within the criteria, and in PE I'm commanding above the max., plus flowing more air than max. etc.

Could it be real that there's a bug in some OS? Causing these tests to take place in open loop as well? If there are permanent DTC's for o2 or whatever else, would the ECM really keep commanding these tests?

It's every single time we pass the specific rpm. Not once every drive cycle, every damn traffic light to traffic light. Is it really constantly looking for the test to go complete?

I'd seriously consider purchasing the Tech2Win or SPS gear, but not sure what it's capable of?

Have read that restoring a factory file using the GM software may clear the permanent DTC's, and before you start the car, disable all the o2 codes etc., then the permanents won't pick up?

Any with experience with the Tech2/SPS? Is it as simple as it sounds, purchase a licence, find your file, flash to car with specific cable?

https://gsitlc.ext.gm.com/gmspo/mode6/2017eparms.html

Screenshot (5).png

[sgod1100]

Been doing some more research, along the same lines of inquiry as sgod1100 it seems

There's a mountain of tests the ECM will do at will. Looking through these diagnostic pages, I struggle to find any tests that should still be applied when in open loop.

Quite a few o2 tests (stuck rich/lean in particular) seem to enable above 1100rpm and then disable above 2650rpm. Only problem is they all appear to enable in closed loop, and when I experience the lean spots I wouldn't be meeting the criteria to keep these tests enabled. Even the commanded EQ must be within the criteria, and in PE I'm commanding above the max., plus flowing more air than max. etc.

Could it be real that there's a bug in some OS? Causing these tests to take place in open loop as well? If there are permanent DTC's for o2 or whatever else, would the ECM really keep commanding these tests?

It's every single time we pass the specific rpm. Not once every drive cycle, every damn traffic light to traffic light. Is it really constantly looking for the test to go complete?

I'd seriously consider purchasing the Tech2Win or SPS gear, but not sure what it's capable of?

Have read that restoring a factory file using the GM software may clear the permanent DTC's, and before you start the car, disable all the o2 codes etc., then the permanents won't pick up?

Any with experience with the Tech2/SPS? Is it as simple as it sounds, purchase a licence, find your file, flash to car with specific cable?

https://gsitlc.ext.gm.com/gmspo/mode6/2017eparms.html

Screenshot (5).png

I'm all ears with what you are asking. Weird thing is I DID disable all the tests/dtc prior to starting my car back up after I removed the cats and still having the lean issue. I do have a question that maybe you can answer. I scanned my dtcs and noticed that fuel system, evap, o2 sensor and o2 heater are all "incomplete". I'm assuming the 02 sensor/heater is referring to the down stream o2s. Is that the way they should be read with everything disabled for the cats? I didn't disable anything having to do with the evap system....or is that just connected to the disabling of the cats? These "incomplete" emissions do come back every time I scan the car

Emissions.jpg

[JayRolla]

I'm all ears with what you are asking. Weird thing is I DID disable all the tests/dtc prior to starting my car back up after I removed the cats and still having the lean issue. I do have a question that maybe you can answer. I scanned my dtcs and noticed that fuel system, evap, o2 sensor and o2 heater are all "incomplete". I'm assuming the 02 sensor/heater is referring to the down stream o2s. Is that the way they should be read with everything disabled for the cats? I didn't disable anything having to do with the evap system....or is that just connected to the disabling of the cats? These "incomplete" emissions do come back every time I scan the car

Emissions.jpg

Thats what I was wondering. If these incompletes are causing the issue. I really thought it might be I didnt disable before firing car up and I got worried because I read afterwards that sometimes those permanent codes may never go away if you do that. But sounds like you did disable everything before 1st fire up.

This is one of the most annoying issues.

[L1FTD]

I'm all ears with what you are asking. Weird thing is I DID disable all the tests/dtc prior to starting my car back up after I removed the cats and still having the lean issue. I do have a question that maybe you can answer. I scanned my dtcs and noticed that fuel system, evap, o2 sensor and o2 heater are all "incomplete". I'm assuming the 02 sensor/heater is referring to the down stream o2s. Is that the way they should be read with everything disabled for the cats? I didn't disable anything having to do with the evap system....or is that just connected to the disabling of the cats? These "incomplete" emissions do come back every time I scan the car

Emissions.jpg

When you scan the DTC, do you do it straight after a flash and startup? Or have a decent (~30min.) drive and then scan? Might be a stupid question.

If you have just flashed a tune, will need to go for a drive and scan at the end. Plenty of posts about the lengthy drive cycles required to complete all these tests, but strangely enough I flashed a tune and had a 20min. drive and mine were all done.

Currently, all my o2 sensor 2 is set to no error reported and ses box checked.

Not checked mine in a long time (until a couple days ago), I have always been incomplete on Oxygen Sensor and Oxygen Sensor Heater, and that is still the case. All other tests were complete and no permanent DTC.

At a guess, you might need to go for a drive and scan at the end before engine off. Catalyst and oxygen sensor ones will be connected, but evap and fuel system are on their own, should come good.

I might try doing all the o2 sensor 1 codes and anything related to o2 rich/lean to no error as well. See if I can complete the oxygen sensor and heater tests. Currently running in full time open loop anyway.

Seems to be a dark art, getting the right combination of ses checked/unchecked, no error etc. on the right codes.

[sgod1100]

When you scan the DTC, do you do it straight after a flash and startup? Or have a decent (~30min.) drive and then scan? Might be a stupid question.

If you have just flashed a tune, will need to go for a drive and scan at the end. Plenty of posts about the lengthy drive cycles required to complete all these tests, but strangely enough I flashed a tune and had a 20min. drive and mine were all done.

Currently, all my o2 sensor 2 is set to no error reported and ses box checked.

Not checked mine in a long time (until a couple days ago), I have always been incomplete on Oxygen Sensor and Oxygen Sensor Heater, and that is still the case. All other tests were complete and no permanent DTC.

At a guess, you might need to go for a drive and scan at the end before engine off. Catalyst and oxygen sensor ones will be connected, but evap and fuel system are on their own, should come good.

I might try doing all the o2 sensor 1 codes and anything related to o2 rich/lean to no error as well. See if I can complete the oxygen sensor and heater tests. Currently running in full time open loop anyway.

Seems to be a dark art, getting the right combination of ses checked/unchecked, no error etc. on the right codes.

I did scan shortly after a flash this morning..so maybe that was the reason. So I wonder why my fuel system and evap aren't good....hmmm. Then again I've been flashing the car so much I haven't had a chance to check the dtcs after a decent drive. I'm driving for a decent distance today so I'll check on Sunday when I get back.

My dtcs are set to no error reported with SES UNchecked. Worth a shot at setting all the 02 rich/lean to no error. I'm really wondering if it's those two tests that are messing up our worlds....lol. Let us know if you decide to disable all the 02 sensor 1 stuff

[Cringer]

sgod created an OLSD tune and the lean spot was there. So I don't think CL O2 tests would be part of this.

[GHuggins]

Been doing some more research, along the same lines of inquiry as sgod1100 it seems

There's a mountain of tests the ECM will do at will. Looking through these diagnostic pages, I struggle to find any tests that should still be applied when in open loop. Here's the deal. O2 test or "comparisons" take place even in open loop. Take the rear O2's, hang them in fresh air and go do a wot pull. Guarantee it fails the precat O2's as it will leverage more toward believing the leaner of the two bank to bank and it'll go into permanent open loop because of this. I DO NOT know the specifics of how every test runs. Don't know if this is related or not, but it is a boosted application and GM did take "extra" caution because of that.

Quite a few o2 tests (stuck rich/lean in particular) seem to enable above 1100rpm and then disable above 2650rpm. Only problem is they all appear to enable in closed loop, and when I experience the lean spots I wouldn't be meeting the criteria to keep these tests enabled. Even the commanded EQ must be within the criteria, and in PE I'm commanding above the max., plus flowing more air than max. etc. Closed Loop Diagnostic Max RPM - 3000 / Post O2 sensor diagnostic Max rpm (notice it doesn't mention closed loop) - 5000

Could it be real that there's a bug in some OS? Causing these tests to take place in open loop as well? If there are permanent DTC's for o2 or whatever else, would the ECM really keep commanding these tests? Yes, It commands them over and over again until they pass

It's every single time we pass the specific rpm. Not once every drive cycle, every damn traffic light to traffic light. Is it really constantly looking for the test to go complete? ^^^ Yes

I'd seriously consider purchasing the Tech2Win or SPS gear, but not sure what it's capable of?

Have read that restoring a factory file using the GM software may clear the permanent DTC's, and before you start the car, disable all the o2 codes etc., then the permanents won't pick up? There may be a way around it - set every O2 related and trim related DTC to no error then retest.

Any with experience with the Tech2/SPS? Is it as simple as it sounds, purchase a licence, find your file, flash to car with specific cable,Yes, I was a GM tech for nearly a decade - it is that easy, but may not fix the problem......

https://gsitlc.ext.gm.com/gmspo/mode6/2017eparms.html

Screenshot (5).png

[L1FTD]

Great info, thanks GHuggins! There's so many damn tests in those diagnostic pages, eyes were getting sore trying to scan through and find any relevant to open loop.

If we had permanent codes, the Tech2/SPS might help out for a flash back to stock. As you say, might be a waste of time and money anyway, not 100% the problem is these tests yet.

Is there anything out there that can allow disabling of tests (beyond what HPT used to provide)? Wishful thinking If it was that easy, this thread would probably be a lot shorter.

Only two things I've tried, have kept the AFR smooth through these spots.

- Throw fuel at it with PE or OL Gain; spikes gone, AFR good, EQ error bad. Not ideal, masking, but works.

- Lower fuel pressure, no additional fuel beyond VVE humps; spikes smoothed only for WOT. Hurts tip-in, need the opposite when hitting the throttle with boost, nothing for part-throttle.

Maybe this problem has always been with us from stock, then add big injectors that don't spray at an angle, and we go way leaner than GM ever intended/saw.

Be good if there was an injector flow rate vs. rpm modifier. The Evap. factor gain multiplier is by RPM, tried playing with that. It has an effect, but I think everything needs to come together to hit the right spots (evap., impact, transients all happy). Can see in the log, part-throttle and AFR goes rich then back up. Could spend a bit more time on that and try and hit the whole lean spot.

Will try a few more things over coming days

Screenshot (6).png

Evap. Factor Gain.hpl

[L1FTD]

I did scan shortly after a flash this morning..so maybe that was the reason. So I wonder why my fuel system and evap aren't good....hmmm. Then again I've been flashing the car so much I haven't had a chance to check the dtcs after a decent drive. I'm driving for a decent distance today so I'll check on Sunday when I get back.

My dtcs are set to no error reported with SES UNchecked. Worth a shot at setting all the 02 rich/lean to no error. I'm really wondering if it's those two tests that are messing up our worlds....lol. Let us know if you decide to disable all the 02 sensor 1 stuff

Will definitely try disabled on every o2 and trim related DTC If that doesn't get Oxygen tests completed, maybe even do every single DTC and let it idle and see how that goes. Beyond that, back to square one.

[GHuggins]

What doesn't make sense to me on all of this is "technically" the post O2's are supposed to be disabled with killing the post O2 test - in other words the test aren't even supposed to take place, but everything is saying the test are still in play with what people are saying on here with this starting right after messing with the cats or O2's. I know just because something is in a calibration doesn't mean it actually has the hooks for the setting changes to work. Maybe what's going on here - hooks not in place for it to work? Every calibration out there has manual and auto calibrations in them for example, but only one is used... It could even be something real stupid like a different test for something completely un-associated taking place where it's looking for certain fuel changes. At this point I'm not throwing anything out.

After killing the necessary dtc's you should be able to do a key on engine off dtc check and it show that they've passed.

[L1FTD]

What doesn't make sense to me on all of this is "technically" the post O2's are supposed to be disabled with killing the post O2 test - in other words the test aren't even supposed to take place, but everything is saying the test are still in play with what people are saying on here with this starting right after messing with the cats or O2's. I know just because something is in a calibration doesn't mean it actually has the hooks for the setting changes to work. Maybe what's going on here - hooks not in place for it to work? Every calibration out there has manual and auto calibrations in them for example, but only one is used... It could even be something real stupid like a different test for something completely un-associated taking place where it's looking for certain fuel changes. At this point I'm not throwing anything out.

After killing the necessary dtc's you should be able to do a key on engine off dtc check and it show that they've passed.

Yeah definitely sounds plausible. Cat test disable might not do anything on the LSA, or certain LSA, who knows. There?s enough stories of mislabeled or redundant tables in HPT, could be the case.

Doubt HPT would be willing to investigate anything emissions based anymore.