Fuel Trim Readings?
 

Let me give some history with what I have done and some of the readings I have gotten.

I installed new FI HFC and TDX the first week in Nov. In my rush to install it I disconnected the battery late in the install and had my son press the brake pedal to clear the ECU. Another thing in the rush to get it on the road to heat cycle the exhaust was I forgot to connect the passenger side MAF plug. I drove it about 500 feet then realized what I had done and connected it with the car running. I should mention that the ECU clearance cleared my trip computer and clock but I retained my radio settings.

I run the torque APP on my phone and have several things being displayed but, want to ask about the Fuel Trim Bank 1 (Short Term) Fuel Bank 2 (Long Term) and the same for Bank 2.

When logging at start up my Short Term bank 1 and 2 would read different. The displayed range fluctuates alot but they were never cycling the same one going up one down or the numbers were 4-5 digits different same for bank 2.

Tonight I installed a stillen Gen 3 and disconnected the battery first thing. This time it cleared everything and the radio settings as well. Just got back from a drive and when my ECU relearned its self the bank 1 and 2 reading are cycling the same and are about 20 digits different. Before at idle speeds they would read 4.something now 27. something then they slowly fall lower but together which looks like what they should be doing. The long term cycle for both I assume are for higher RPM's more throttle etc..

I'm not sure how accurate the torque app is but, I would think on everything that is read from the ECU it should be pretty close.

Does anyone know what the normal cycle numbers are for the Bank 1 & 2 short/long term fuel trim readings should be? I would think they should cycle the same numbers from side to side.

Car feels like it has more torque the horsepower readings are based off of the phone accelerometer and your car profile so I don't throw much stock in those readings.

Thanks

Oh and Huck if you read this thanks for your vid on the stillen install.

Can you give anymore details on the readings you were getting?

Leaks on both the intake or exhaust system can make the fuel trims off bank to bank.

If your seeing more than a 5% difference from bank to bank then you defiantly have some short of issue / leak.

As for how accurate the trq APP is - no idea

John

I will go ch2ck it again today and get some numbers. I dont think I was 5% out from side to side. I will recheck the connections from the cats just to be safe.

Got some readings today.

Car at operating temp:

At Idle

Bank 1

Short 4.1 to 8.6
Long .8

Bank 2

Short 4.0 to 10.9
Long 5.5

At 3000 rpm driving I was only able to get the long while driving.

Long 1.6 to 4.7 Long .8 to 7.0

Bank 1 short tends to run on average higher than bank 2 short and Bank 2 Long runs higher than bank 1 long. I will get it in the air tomorrow ans check for any exhaust leaks I guess. Although the above readings are measured in % so they would be within 5% even though the highs and lows maybe more.

Any thoughts? Not knowing how much fluctuation is normal I may be over analyzing it.