2012 Nissan Pathfinder SV - Fuel trims-I need a sanity check *B1 higher than B2

Ok, so here's what I got:

2012 Nissan Pathfinder SV 2WD
VQ40DE (V6) - 150,000 miles.

I just purchased the car almost exactly a month ago.. Annndd.. It's been a bit of a pig. I got screwed but long story short this wasn't supposed to be a fixer and I consider myself smart enough to check stuff out, however.. The lot mechanics must have known what I was looking for and made sure it looked the part. Welp. I found out that was NOT the case but here we are.

So here's the issue and backstory:

Backstory.. Well, here goes.... Just got it but off the hop, I noticed the engine was running rough at idle once I got it home. Checked everything and all fluids look good. Found a coil was not seated properly on cylinder #2 (missing screw). went to take the coil off and it was trashed. It broke in two just from gently trying to lift it. Had to literally dig most of the rest of it out of the hole (thank goodness it all came out). So I decided well, it's for sure been misfiring on that cylinder so I bought a plug as well. Took the plug out and found out it wasn't the right size (or even one called for the engine). Luckily whoever put it in there at least put in one that was the right thread count. Once i noticed that and replaced the plug and coil, it ran better but.. Still not quite right.

I decided I would replace all coils and plugs at that point because well.. Those were just some red flags for sure. So I did. Cylinder #1 (have to take intake off to get to it which I replaced the seals at that point), coil came out OK, but spark plug was CLEARLY the one from factory. I had to use a good bit of PB blaster and working it back and fourth to loosen enough to be comfortable attempting to take it out without it breaking off into the head. VERY VERY LUCKILY it came out. It had a good bit of what looked like chared oil on a part of it. Not new oil at all. As if someone replaced the valve cover gasket or accidently poured oil down the spark plug hole with the plug still in it at some point but just put the coil back on top like they didn't care.. All other coils and plugs came out as per normal. I used NGK OEM type plugs for the new plugs and Duralast OEM style ignition coils.

At that point it ran BETTER. Quite a bit better for sure buuttt.. Still not running right or at least seemingly.

A week later the exhaust flange broke off on the driver's side exhaust manifold..

I replaced both side manifolds. Also while doing that, I found that both primary cats were bad. *Preface I don't live in an emissions state*. I busted them out (primary and secondary) because this is my daily driver and it has to run. Since putting it all back together yeah I have exhaust leaks but outside of that it does run EVEN BETTER but it still seems to be something odd about it's idle at least. Revving sounds very healthy. I am replacing the catalytic converters today (literally I have everything unbolted just need to take the old ones out and put the new ones in and new seals/hardware etc).

But in between I come to where I am now. Perplexed by this: My STFT on Bank 1 are higher than Bank 2. Not enough to throw a code but definitely higher. And yes maybe it's due to no cats which hopefully will resolve something with that today but I'm feeling like it will not.



A clearer image of this happening:


I made a video. This starts with me idling in the driveway and going on a 10 minute-ish drive with a little revving in between. At times it will stablize and the STFT for bank 1 and 2 will be in unison (obviously opposite each other) which is what I figure it should be.


Let me know you guy's thoughts on this.
This is the video going on the drive:
photos.google.com/share/AF1QipP75wpS10J8...dUREZXVlU3NzSFBFOWhB

This is the video sitting idle (After the drive):
Fuel trim video link

I feel it's possible that it's all in my head at this point but I need some clarity if that is the case. I listened to a few videos of 4.0L idling with misfires and that is distinct. I don't feel mine is, but figured I would see what you guys think of my STFT. I know that's not a lot of data. I'm having to use basically a screen recorder on my android phone to get the graphing over time while driving and adding in more than a few sensors makes it very hard to follow and in cases like adding RPM, it makes it much less granular.

If it's anything extra, I cleaned the throttle body (haven't replaced gasket but will be doing that today). I have not replaced O2 sensors but I don't know what they are supposed to look like at this point. Not until I put the new cats on it today anyway. Fuel consumption is as I would expect I suppose. Hard to know what values it should be when it never ran right in the first place..

I did test for vacuum leaks spraying carb cleaner on anything that could affect it and no change of anything so I do not believe that would be an issue. Outside of that it's just been mechanical issues I have been dealing with (oh god there is a laundry list for sure).

Also I have what I feel is a temperature issue. It gets up to 214 F at times idling generally staying around 200 to 208. It's been something I noticed forums going round for round with this engine. Some say that's perfectly in spec, others swear their VQ40DE runs at 180 no higher than 195..

I have not serviced the cooling system. I know the fan clutch is good and it does have coolant (not blue OEM coolant).

Reason why I am worried is because I'm going for a 2400 mile round trip in October and I will be hauling a uhaul trailer back so I am just trying to furiously get this thing beat into shape as fast as I can.

Lastly my vacuum does move a little between 15 and 18 while idling. Otherwise it rises and falls as normal. Or as far as I know.

I hope that's enough info for you guys! I have done research on fuel trims, checked for vacuum, and I understand either it's bank 1 running leaner than normal or bank 2 running fatter than normal but just not sure if this abnormality is normal and I'm just chasing my tail here.

Your trims look fine, anything under 10% or over -10% is considered within an acceptable range. It's common for one bank of an engine to have a different trim than the other bank and any number of things can be a factor to change the fuel trim up or down a few percentage points.

Okay so one STF is averaging around +5 the other on around +2 --- nothing crazy there but what you have to look at is the the sum of the STF and LTF for each bank, anything under plus or minus 10% is considered OK. Looking at the pattern of the the STFs it looks like the upstream O2 sensor are working fine but if you want to to confirm look at the graphs of B1S1 and B2S1

Your running temperature will vary depending on the thermostat fitted frequently different thermostats are fitted depending on the market the vehicle was imported into and year of manufacture. If you leave any gasoline engine running at idle the temperature will rise above thermostat temperature until the fan cuts in.
So I would
(1) Check the fan clutch operation against the specified temperatures for fan speeds cut in and cut out.
(2) There is an 82c (180f) thermostat listed by Gates for this engine and a 77c (170f) listed by Meyle --- check with your Nissan parts supplier.