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Bank 1 is the right side of the engine (Passenger side in NA), Bank 2 is left side of the engine, (drivers side in NA). The SC engines have a separate SC cooling system so the temp 2 reading may be coming from the coolant temperature on the SC loop) Your Bank 1 fuel trims are slightly lean but still in the good zone, your Bank 2 fuel trims are way lean, and if you don't have it now, you will probably be seeing the P0172 pre cat lean DTC soon.
 

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Discussion Starter #22
Bank 1 is the right side of the engine (Passenger side in NA), Bank 2 is left side of the engine, (drivers side in NA). The SC engines have a separate SC cooling system so the temp 2 reading may be coming from the coolant temperature on the SC loop) Your Bank 1 fuel trims are slightly lean but still in the good zone, your Bank 2 fuel trims are way lean, and if you don't have it now, you will probably be seeing the P0172 pre cat lean DTC soon.
If I’m not mistaken, a negative LTFT means the bank is running rich, and it’s reducing the percentage of fuel from base map. I am running rich, not lean..
 

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I think it depends on how you are getting your LTFT data, SDD shows lean as positive numbers and rich as negative, but a generic code reader shows lean as a negative number and rich as a positive number.
 

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Discussion Starter #24
I think it depends on how you are getting your LTFT data, SDD shows lean as positive numbers and rich as negative, but a generic code reader shows lean as a negative number and rich as a positive number.
Using IIDT tool. So negative should be a rich condition.
 

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Agreed, should be running rich. Which points to things like a plugged up (dirty) air filter, a (or multi) failed injector, maybe a dirty throttle body which on the 09 and previous L322 SC engines are a bit of a pain to get to being in the rear of the intake manifold (don't know where they are on a 5.0 engine) or possibly just a messed up ECU program telling the injectors to pump more fuel that is actually required. What kind of numbers are showing up on your pre cat O2 sensors. Do they indicate a rich mixture, or do they seem reasonable?

If the CAT with the 0420 code is really plugged the engine can just be struggling to make up for the loss of power caused by less exhaust flow on that side. I had a cat plug on a throttle bodied engine years ago and it was like I have lost 1/2 the cylinders, and i bet that CAT glowed bright red before it completely burned out.
 

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Discussion Starter #26
Agreed, should be running rich. Which points to things like a plugged up (dirty) air filter, a (or multi) failed injector, maybe a dirty throttle body which on the 09 and previous L322 SC engines are a bit of a pain to get to being in the rear of the intake manifold (don't know where they are on a 5.0 engine) or possibly just a messed up ECU program telling the injectors to pump more fuel that is actually required. What kind of numbers are showing up on your pre cat O2 sensors. Do they indicate a rich mixture, or do they seem reasonable?

If the CAT with the 0420 code is really plugged the engine can just be struggling to make up for the loss of power caused by less exhaust flow on that side. I had a cat plug on a throttle bodied engine years ago and it was like I have lost 1/2 the cylinders, and i bet that CAT glowed bright red before it completely burned out.
Blower and throttle body have been off and re sealed/cleaned. the Bank 2 pre-cat 02s showing -11 to -14% under light load. -5 to -8% on medium to heavy loads. Bank 1 is always around -1% to -3%. sometimes zero.

The Bank 1 cat : pulled it out, scoped and inspected, and found some physical exterior damage from off-roading, and a tiny sliver of honeycomb was missing inside. Not plugged. Bank 2 looks fine. so its seems like an un-related problem.

Now I just drive around comparing whatever parameters I can to find more anomalies, and noticed the following:

Valve timing (VCT): both banks equal, within 1 degree, changing timing as requested by PCM
Valve lift control (LR Speak: CPS, aka Camshaft Profile Switching) not working. I never get into high lift mode when under high load and high RPM. always staying in low-lift mode, no matter what

When I check for misfire counters on individual cylinders, I dont get anything. When I check for total combined events, I get a number showing.

When I check the parameter for "Combined misfire information - fuel cut-off execution flag bank1 (or bank 2), i get activity here. But I get Bank 1 showing "true" for this on occasion..
Is there a better way to see if I am getting misfires?

If bank 2 has its own HPFP on its own circuit, maybe that is the cuplrit.. because from what I can see, there is only one pressure sensor, and its on the Bank 1 circuit.
 

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A misfire (or multiple misfires) are obvious when driving as the vehicle will judder as the misfiring cylinder(s) drop off and exhibit themselves.

Are you experiencing any juddering under different throttle/rev settings?

Does the car drive normally during cold start then begin any pronounced judder when driven (at any particular RPM ie 1800rpm on the highway) once it's reached normal operating temperature?

Are your normal operating temperature cylinder compressions all in the 180-200 psi range?

Are you using SDD as the diagnostic platform?

If you're using SDD there are a couple of ways to detect/monitor misfires.

Given that you're aware of your VVT angles it's likely you're using the less capable of the two options. I'm guessing the page you reference has the VVT angle readings across the top and the eight individual cylinder references below in two horizontal columns?


Rob
 

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Discussion Starter #28
A misfire (or multiple misfires) are obvious when driving as the vehicle will judder as the misfiring cylinder(s) drop off and exhibit themselves.

Are you experiencing any juddering under different throttle/rev settings?
Juddering, no. just RPM fluxuation

Does the car drive normally during cold start then begin any pronounced judder when driven (at any particular RPM ie 1800rpm on the highway) once it's reached normal operating temperature?
Drivability is roughly the same when warm or cold. Cold start gets a little high on RPM (revs too high and stays kinda high). But this symptom also occurs when hot, just not as bad.

Are your normal operating temperature cylinder compressions all in the 180-200 psi range?
Have not done a compression test yet.

Are you using SDD as the diagnostic platform?
No, using GAP tool.

If you're using SDD there are a couple of ways to detect/monitor misfires.

Given that you're aware of your VVT angles it's likely you're using the less capable of the two options. I'm guessing the page you reference has the VVT angle readings across the top and the eight individual cylinder references below in two horizontal columns?


Rob
No, just using IIDTool, which lets me pick any 8 parameters I want.

Going back in to my repair shop to check the fuel pumps and a few other things

Also, just a side note - while the S/C was off for VVT actuator replacement, I had the intake valves walnut blasted. All clean now. They weren't horrible, but weren't great.
 

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OK,

Here's a printed out copy of the SDD screen results of the two depictions I was referring to (below).

I was working on this normally aspirated MY2010 5.0 this past Saturday. Note, the car is running during both tests.

The panel with the VVT displays zero misfire(s) while idling in the shop, yet the second more appropriate panel with just the misfire detection annotated data selected displays multiple misfires during a follow-on road test with an observer.

VVTplusmisfire1justmisfire2.JPG

activemisfire detection.JPG

If the shop you're using has SDD make sure they/you use the second/lower option and have TWO people on board, then take the vehicle for a test drive to monitor the data regarding possible misfire(s).

One person drives, the other monitors the data from the passenger seat (unless you almost want to guarantee a wreck).

The "Current column" is the number of misfires during THAT drive. The "Average column" is a cumulative detective record and although it may look less bold in the printout, the left side number is actually depicted in green on the computer.

Before going any further, it's worth taking the time to do a compression check prior to spending any more money on parts - you need to make sure the motor is mechanically "well enough" as is.

Good luck,

Rob

PS The first thing I did on this vehicle was check its normal operating temperature compressions (all good). No point trying to troubleshoot an external issue if the thing's worn out on the inside :)
 

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Discussion Starter #31
OK,

Here's a printed out copy of the SDD screen results of the two depictions I was referring to (below).

I was working on this normally aspirated MY2010 5.0 this past Saturday. Note, the car is running during both tests.

The panel with the VVT displays zero misfire(s) while idling in the shop, yet the second more appropriate panel with just the misfire detection annotated data selected displays multiple misfires during a follow-on road test with an observer.

View attachment 271894

View attachment 271896

If the shop you're using has SDD make sure they/you use the second/lower option and have TWO people on board, then take the vehicle for a test drive to monitor the data regarding possible misfire(s).

One person drives, the other monitors the data from the passenger seat (unless you almost want to guarantee a wreck).

The "Current column" is the number of misfires during THAT drive. The "Average column" is a cumulative detective record and although it may look less bold in the printout, the left side number is actually depicted in green on the computer.

Before going any further, it's worth taking the time to do a compression check prior to spending any more money on parts - you need to make sure the motor is mechanically "well enough" as is.

Good luck,

Rob

PS The first thing I did on this vehicle was check its normal operating temperature compressions (all good). No point trying to troubleshoot an external issue if the thing's worn out on the inside :)
I agree - will have them rule out mechanical internal problems. Can you post larger versions of those photos? they are too small to read. or email if you can.
 

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Can you read oil temperature? About the only thing I can find that would inhibit the high lift cam profile switching is an oil temperature below 20C. I would assume the solenoids that activate the switchover, are monitored for shorts and opens by the ECU so there should be some kind of DTC if those were electrically bad.
 

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Discussion Starter #34
Can you read oil temperature? About the only thing I can find that would inhibit the high lift cam profile switching is an oil temperature below 20C. I would assume the solenoids that activate the switchover, are monitored for shorts and opens by the ECU so there should be some kind of DTC if those were electrically bad.
Yes, oil temp comes up. I did the test when everything was full hot (its around 75F in So Cal these days :) )

It is strange, but maybe the parameter I selected was wrong? But I followed 2 parameters - one for the position, and one for the request, neither every moved away from the "low" setting even at WOT/Redline
 

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Typically, when an issue is detected, the system will generate a "freeze frame," which will store all of the engine parameters at the time of the event. What I suspect here is an issue of ignition misfire, either due to coil packs dying, or leaking spark plug wires. What I typically see with engines with more that 50-60,000 miles on the clock and a misfire, is that the spark is leaking around the plug wires to ground, or the coil is arcing internally. There are several things causing off-idle misfire; one is that the mixture leans out off-idle. Yes, it stays at 14.7:1, but there are issues with effective compression, in other words, better cylinder filling off-idle, requiring more spark voltage to fire the plugs. The other thing causing higher effective compression is spark advance, which again raises effective compression. So does the cam timing, as it is creating EGR, which controls NOx. All of these conditions raise required voltage, and the resulting higher voltages can stress ignition components to the point of arcing. It is also possible for one or two plugs to have cracked insulators, causing arcing. If the codes indicate which cylinders are misfiring, you can use the codes to isolate the faulty components. Chances are that if one or two cylinders are the culprit, the others will soon follow. Ray
 

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Discussion Starter #36
Typically, when an issue is detected, the system will generate a "freeze frame," which will store all of the engine parameters at the time of the event. What I suspect here is an issue of ignition misfire, either due to coil packs dying, or leaking spark plug wires. What I typically see with engines with more that 50-60,000 miles on the clock and a misfire, is that the spark is leaking around the plug wires to ground, or the coil is arcing internally. There are several things causing off-idle misfire; one is that the mixture leans out off-idle. Yes, it stays at 14.7:1, but there are issues with effective compression, in other words, better cylinder filling off-idle, requiring more spark voltage to fire the plugs. The other thing causing higher effective compression is spark advance, which again raises effective compression. So does the cam timing, as it is creating EGR, which controls NOx. All of these conditions raise required voltage, and the resulting higher voltages can stress ignition components to the point of arcing. It is also possible for one or two plugs to have cracked insulators, causing arcing. If the codes indicate which cylinders are misfiring, you can use the codes to isolate the faulty components. Chances are that if one or two cylinders are the culprit, the others will soon follow. Ray
Thanks for the info. As it turns out.... the S/C engines DO NOT use cam profile changing (according to my LR tech). Just VVT. Also, HPFP test performed, everything working well, right on spec. I just wish these f-ing problems would be more apparent.

I am not getting any misfire codes.. Just have tried to see if any are showing up. Plugs and Injectors are new, i think coils are original.. although I would think a bad coil would throw some kind of code.

They are telling me that due to the bad CAT.. (P0420), the tune is being thrown off. I have a hard time believing that. He says the system is constantly pulling timing and enriching/leaning the mixture in order to determine if there is a misfire or other issue and develop another code.
 

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One thing I noticed while perusing the previous pages was the apparent disagreement between TPS readings. Does this engine have two throttle bodies? Can you clarify the two TPS readings? I tend to agree with you re: the cat issue, but if one side is partially restricted, the resulting imbalance in the exhaust may cause the ECM to start "guessing" about what is going on. Let's start with the TPS issue. The Po420 code relates to the cat's ability to store O2. If the system is attempting to provide more O2 to that cat, it WILL lean that bank in an attempt to provide more O2 to that substrate. That makes more sense to me that the gibberish the tech handed you. Ray
 

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The downstream O2 sensor connectors attach to mounting clips close enough to each other at the rear of the transmission that you could easily mark them and then "swap" them (the connector plugs) Left side rear O2 to Right side rear O2, and Right side rear O2 to Left side rear O2, and see if the "cat problem" compensation swaps sides too.

What were the results of the compression test?

Rob
 

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Discussion Starter #39
One thing I noticed while perusing the previous pages was the apparent disagreement between TPS readings. Does this engine have two throttle bodies? Can you clarify the two TPS readings? I tend to agree with you re: the cat issue, but if one side is partially restricted, the resulting imbalance in the exhaust may cause the ECM to start "guessing" about what is going on. Let's start with the TPS issue. The Po420 code relates to the cat's ability to store O2. If the system is attempting to provide more O2 to that cat, it WILL lean that bank in an attempt to provide more O2 to that substrate. That makes more sense to me that the gibberish the tech handed you. Ray
Only one TB. I think it has two sensors for redundancy/fault finding. The thing is, the P0420 is for Bank 1. The rich bank is bank 2. Ordering an OEM cat to finally eliminate the problem. Someone from GAP said they had a similar issue on a L322.
 

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Discussion Starter #40
The downstream O2 sensor connectors attach to mounting clips close enough to each other at the rear of the transmission that you could easily mark them and then "swap" them (the connector plugs) Left side rear O2 to Right side rear O2, and Right side rear O2 to Left side rear O2, and see if the "cat problem" compensation swaps sides too.

What were the results of the compression test?

Rob
Tests all came back good. Fuel pressure is spot on. Told me to get a new cat and recheck from there. Wish there was a better option vs 1300 bucks for one.

While waiting for the cat., I am going to continue to monitor other parameters to see if I notice any more anomalies. I am getting 1-4 misfire counts every now and then on Cyls 2,4,6,8 (note, I am only monitoring that side, for misfires resulting in catalyst damage, and misfires resulting in emissions problems, 2 parameters per cyl, max 8 on IIDtool). Cyl 6 seems to be the most finicky, followed by 4 and 2. Misfires are mostly when at low RPM /Low load. WOT or high load shows zero. Will monitor bank 1 to see if there is a diff
 
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