On going intermittent engine fault

Apologies if order is a bit jumbled, turned into a bit of an essay . Moved a few sections around.
Roughly, its
-Symptoms
-attempted fixes
-symptoms in detail
-Fixes in detail / Intermittancy

Have a second hand 2014 street triple R that ive taken to the garage several times.
The symptoms are: (all intermittent see bottom of message)
1. Unstable dropping idle
2. Very low speed/filtering stalling (I believe linked to 1.)
3. Varying fuel mixture (most noticeable when it runs VERY rich)
4. Steady speed drop in power. (also linked to 3.)

The garage also fiddled with a couple of bits on the bike, ECU, throttle body etc. I'v also inspected the air filter and spark plugs. Brief look at the inductor coils, but dont know to much about them.
Im currently looking at the Lambda sensor, clean but still believe is faulty but not displaying an error code. I recall reading the thermistor can function, but give out the wrong voltage.
Though im a little stuck here as the 2014 street triple is annoyingly hard to work with. I tried to remove the sensor but it goes into a 46-pin connector, not the usual separate socket on the engine. I also tried the TUNEECU program, but again the 2014 model uses it own wiring arrangement...
Next step is to put a pin through the lambda sensor wires and measure voltage.

1. Most obvious pulling up at traffic lights. Occasionally the engine RPM slowly starts to drop. I've notice that the bike corrects itself if it drops below 1000rpm.

2. Didn't notice it too much until i commuted through london. The 1-5mph filtering of brief throttle uses caused it to stall quite often. (current ECU set up has almost cured this)

3. Changes between running fine, to lumpy. Running smoothly with quiet popping, caused by sport exhaust. To masses of huge exhaust pops, 4-8 each time i shut the throttle, wouldn't goes as far as a back fire. I believe this is called 'searching'?

4. Every once in a while cruising at 20-40mph, you can hear from the exhaust the engine beginning to run rich. Then about 20% loss in power... So adjust throttle accordingly and ignore it burbling. After a minute or two it will revert back, so 20% power gain. Annoying when trying to stay at one speed.

The bike came with a stock exhaust, which muffled the fuel mixture symptoms. So was looking in the wrong places for a while. However i currently have a Scorpion exhaust so i can hear when the engine begins to run rich. The same noise when tuning-in a RC car i used to have. That and the small gun battle that occurs when i shut the throttle lol.


I think the main reason its not been diagnosed is the fault/s only occur 10-20% of the time. Some of the time it runs fine, just the occasional quiet popping caused by a sport exhaust.
When i take it to the garage they turn it on and go 'nothing wrong with that mate' (i did get them to do the below though)

The intermittentancy is also why im finding it difficult to diagnose myself. Most faults would be constant, e.g. air filter, fuel lines etc.
My thoughts on intermittent causes were the ECU, perhaps the previous owner changed the map. So i had the garage try all three ECU maps. Stock/OEM Sport Exhaust(the arrow one)/ OEM 3rd party exhaust. Im currently running the most stable combination of OEM Sport with my Scorpion. It has at least reduced the stalling issue.

 

Just an update after playing around with lambda sensor at weekend.

4.8V sensor reference, which according to the manual is ok. With bike running it dropped to 1V. Then slowly kept dropping, it got to 0.78V before the neighbor complained of the noise lol. (10mins or so)
Below 0.8V the engine idle speed also started dropping. Below 1000rpm it reset its self back to norml (1600ish)

I guess that means the lambda is not at fault? Any ideas what else might cause intermittent fault. Next stop is a specialist tuning shop, but guessing will cost a lot

 

Ok thanks, will contact him. Though im kent based, so might see if he recommends anyone around here.

Problem im having is the garage appears to be primarly a sales/service centre. Any unusal problems they contact Triumph, though that was 2months ago. From what i heard the Triumph repair/warranty support team is only two guys...

 

Anyone still following? ha
Found out the problem was linked to Lambda sensor that had failed 'good'. By that i mean the bike showed it working ok, two garages said it was working and i even multimetered it out and appeared to be working!

I switched in a "spare" *cough* from a Daytona and its idling ok! Well for most part, 2 weeks before swapping the sensor it has started popping like crazy. Check plugs and filter, but mrhh, thats another story for another time.