Freeze frame data...can someone tell me what it means

[John H]

I recently had my torque converter changed because my previous one was giving out, mileage used to be good before the swap. Now the truck exhaust quiet, power doesn't feel the same and mileage is bad. The converter is a rebuilt unit supposed to be stock setup. I'm not saying the converter is the problem but it started when it was swapped. Code p0442
STFT B1 -2.3
LTFT B1 12.5
STFT B2 -3.1
LTFT B2 10.2

 

[Dirtman]

P0442 is an evap system code for a small leak. It would have nothing to do with the torque converter unless a line was broken during the process. It also shouldn't cause any noticeable performance or mpg changes. First thing is to just check your gas cap.

The numbers you gave are your fuel trims and there is nothing wrong with them.

What were the symptoms that originally led you to believe the torque converter was bad?

 

[RonD]

Fuel trims are averaging +9 so not too unusual

STFT is the average at the time of the freeze frame, -2 means O2 sensor was showing computers calculation was a bit Rich so so injector are being closing 2% sooner than calculated to get correct level of Oxygen in the exhaust on that bank
Same for the other bank

LTFT is like it says Long Term average, it should start coming down if the STFT stays in the "-" range
When its at about +9 the STFT should be around 0
STFT should vary quickly between 0 and +5 normally
I don't see this showing a reason for lower MPG


The lower MPG, as far as torque converter, may be because it is not Locking up like it should
One of the benefits of solenoid control in an automatic was locking up the torque converter ASAP to get direct drive, the main advantage of a manual trans and its better MPG than an automatic
If torque converter is slipping once you are moving then you lose MPG and power

 

[John H]

P0442 is an evap system code for a small leak. It would have nothing to do with the torque converter unless a line was broken during the process. It also shouldn't cause any noticeable performance or mpg changes. First thing is to just check your gas cap.

The numbers you gave are your fuel trims and there is nothing wrong with them.

What were the symptoms that originally led you to believe the torque converter was bad?

Started as a vibration and got worse..eventually it started rattling loudly. Replaced the converter and flywheel and it feels smooth again