Toyota Repair: 2001 Camry with p0301 trouble code

Question
Hi Ted,

The other day while at a red light my car started to sputter. It started fine and this was about 2 minutes into the drive. My fuel tank was at about 1/8.  The check engine light started to flash. Got it home and read the code. I tried several things, they are:  changing the spark plugs, #1 was black, definitely burning rich. The others were whitish looking normal for their age. Checked the spark plug wires and checked their resistance.  Checked the coil pack for cylinders 1 and 4 resistance and voltage were fine. Checked the MAP sensor and the throttle position sensor and the engine coolant temperature sensor. All seem fine. Added dry gas and 10 gallons of 93 octane fuel to the tank. I cleared the codes and tried it again, and again it ran fine for a least a minute, then started sputtering while idling in the garage. The freeze frame data did not indicate much.
Rpm 1758,
load 38%,
MAP sensor 37kPa,
ECT 102 deg,
STFT1 7%,
LTFT1 9.3%,
STFT3 -100.6%,
LTFT3 -100.6%.  
Fuel system 1 closed
I thought it may have been the upstream O2 sensor due to the fact that there was a delay between starting the car and when the misfires would start occurring. I tested the resistance of the heater circuit and it was only 1 Ohm, but I have not gotten an error code for that sensor. Throttle body is clean and clear, air cleaner is clean. I replaced the timing belt and water pump at a little over 100,000 miles. I'm now at 180,000. I tested the EGR valve seems to be working fine. I had replaced that about 4 years ago. Finally, I've checked the hoses for leaks and nothing appears to be cracked or disconnected. I appreciate any insight you can give me. Thank you for your time.

Answer
Hello, is this a V6 engine or 4 cylinder 5SF-E? The problem I'm seeing is the fuel trim readings for STFT3 and LTFT3, these are way off, should be closer to 10% or below. I'm a little confused about the "3" designation, it's usually bank1 and bank2 that's why I need to know which engine it has. If it has the 4 cylinder engine I need to know if it has two coils at the cylinder head or a distributor, thanks.