The reset may not be a reset per say but maybe that higher RPMs bring your STFT in expected range for whatever reason we are trying to decern.

The -24.2 is the last value it will give you as the true value is off scale

 

The reason I mention reset is that while the engine is idling the short term Trims will set back to zero and then slowly move back. The engine will momentarily smooth out and then move back to missfires. And this happens over and over and over.

 

What is the LTFT for Bank 1
What is the LTFT for Bank 2

 

Any Check Engine Light codes with the OBD - 2 basic reader ?

Your reader that is giving you live data like your fuel trims as observed

Your reader probably has other parameter IDs ( PID ) that can be looked at

The 4 most important are:

Mass air flow rate

Throttle position sensor

Engine coolant Temperature

and your STFT

At idle for this engine the values are :

TPS : 13 % at idle and moving very smoothly toward 100 at wide open throttle

MAF : 4.5 grams / second at correct idle going up to around 175 on wide open throttle

ECT : at least 88 C after warm up

STFT target of 0 %

Without the reader you can use a common multimeter

With the reader you can record a graph so when at home you can interpret you live data and see what is the cause of your drift

There is a thing if the ECU sees a sensor missing or out of expected range it will reject the sensor and revert to a not optimal set of data maps or arrays until that sensor comes back in range

This takes some time to default back and forth out of best engine regulation

 

Before I threw parts at any other sensor, I used the live data when I bought this car to observe Open loop heavy components such as the Coolant temp, mass air flow sensor and throttle position to indicate if either of those are a fault.
apon viewing the live data 20 mins ago, everything was reading complete nominal and in range. HOWEVER,
before leaving into my gym I hooked up the code reader and read the codes. At idle, this is what they read, STFT B1 0% (GOOD!!) STFT B2 +24% (NOT GOOD) it has been running much better after fixing an exhaust leak and egr leak but still missfired a little and a weird flat loss of power. So, I reset the ECU and turned the car back on.
The fuel trim for bank one was back to -24 and the trim for bank 2 was +24. And it ran noticeably much worse!
also to note, they both rose completely parallel of each other I,E if bank one was -10 bank two was +10 and so fourth up to 24 where it held

This is when i plugged it in before resetting

After resetting

 

On paper 192 F is very very near the tripping point of open / closed loop mode 88 C

The fluid thermostat should hold it a slight margin above the tripping point

So you might be at a thermostat change keeping in mind the thermostat does not take a large O - ring even if it comes with one , cracks the housing on bolt down

You might observe if the ECT waviers below your 192 shown as this would be worse

 

Typically my Ect sits at around 185 degrees.
it's currently about 85 degrees °F where I'm at and I was also idling stationary for a bit.

 

global obd isn’t to be trusted on these cars

 

I've watched these fuel trims do basically the same thing on a Dealer approved scanner.

 

The below 88 C ECT puts you in open loop mode that does not use O2 sensors for engine regulation

There is a way of putting a common meter on the ECT sensor against a calibration graph on page 78

But your observation of 85 F ( warm idle ? ) shows a wide variance explained by .........................

801S TITLE (jagrepair.com)

 

Your ECT return signal is socket Red 14 , Blue / Yellow wire

Look for missing 1 of 2 pinching tabs on the socket

 

I'm going to leave you with this.

STFT should be constantly jumping around. If you have a static number, something is wrong.

Coolant Temp needs to get to 160F or 170F (I forget) before engine can go open loop. Your coolant and it's sensor are in the clear. Cross that off.

If I had to throw a part at this, it would be a new crankshaft position sensor. They are fairly cheap online and you can replace it in about 15 minutes.

 

I actually just changed my CPS last night with, of course, no change in operation. All connections to the ECU are clean and in good condition. I even opened up the ECU case to check all the Caps and soldier Connections for cracks and or corrosion. Everything looks great, PERFECT even. So I'm still at a loss.

 

You mentioned that the oxygen sensors had been replaced as well. Can you read them on your OBD2 device. Like the STFTs, they should be constantly moving. If theres a number that is static, thats a problem.

All four of your oxygen sensors have the same plug. When they were last replaced, is it at all possible that they were switched accidentally? There is no absolute way of checking, since a PDU/WDS can have the ECU "relearn" the orientation of the oxygen sensors. BUT if no one has ever performed that on the car, the following would be connected:

Bank A Upstream has a solid GREEN wire (along with Blue/Purple, Blue/Brown, White/Brown) - The Bank A Downstream has a solid BLUE wire (along with Blue/Purple, Blue/Pink, White/Brown)

Bank B Upstream has a solid BROWN wire (along with Blue/Purple, Blue/Brown, White/Brown) - The Bank B Downstream has a solid RED wire (along with Blue/Purple, Blue/Pink, White/Brown)

Make sure you trace the right sensor wire back to the connection and check these wire colors against what is connected. I would mark each side of the harness and only then, see what happens where you swap out upstreams, then downstreams.

MAF sensor could also be to blame here. Have you tried cleaning it, and checking connections? They make a MAF sensor cleaner spray....

 

The instrument gauge temp indicator is the single wire temp sensor on the thermostat housing

The ECT sensor to the ECU is the 2 wire sensor next to it

Since you have a wide variance on your device that the ECU is seeing at different times you can in this case compare the temps with the inaccurate instrument cluster for a correlation of what state your cooling fluid actually is

I'm going to stick with 88 C tripping point even though I can't find it documented

Vee had the suggestion of giving a slight twist in the MAF sensor connector pin / blades for better contact so it does not " drop out "

 

digging yourself a deeper hole every time

describe the symptoms of your problem and start over

 

Need to confirm his 185 F and 85 F observation.

This should be observable on the other instrument gauge

 

Revisit what b1mcp said. Swapping the O2 sensor plugs and getting them in the wrong sockets is very easy to do, and would seem likely to produce the sort of symptoms you were experiencing.

 

Alright, The MAF is not the problem (I'm observing how it meters air and everything looks correct)

As of now, LTFT for both banks is -10.5

STFT for both banks are flip flopped. If bank one is -24 then bank two is +24. Under WOT they both set to 0.
voltages for b1 and b2 lamba sensors are between 1.00v and 0.985v on both banks (fluctuating)
normally, i see 185 degrees from the ECU when the dash Temp gauge reads one Tick below "normal"

coolant temp sensor new, all new coils, injectors are good, no smoke leak when leak down tested, Crank position sensor is new.

b1 is always taking away fuel and b2 is always adding in some variety or another

 

Lamba is a numerical value with no units with target 1.0

The return voltage of the O2 sensors to the ECU are in the range of 3.5 volts

Do you have the correct O2 sensors installed as they are the different titania technology

Your reader may not read them correctly and default to the more common version


See page 80

801S TITLE (jagrepair.com)

The engine regulation is the rear 2 sensors and the fwd 2 are for Cat efficiency comparison for a CEL code X and Y only

You mentioned you saw 85 F ECT at idle

Did you see a corresponding dip on the instrument gauge

This gauge is not accurate but in this case you can compare to see what your true coolant temp is as an inference