Cylinder 4 misfire and high LTFT

[StopShoe]

I'll start off by saying I don't know a whole lot about what I am looking at in the logs that I have.

My car has a problem with misfiring when it starts cold, always cylinder 4. HPtuners shows it misfires around 80 times, and then once the idle dies down it mostly stops (This doesn't happen on this log because the car was already warm). However, when I let off the gas from light acceleration, cylinder 4 misfires twice. I have a few other cylinders that misfire a few times but I understand that is mostly normal.

I also noticed that my LTFT reads pretty high, anywhere between 15-25%. I got P0171 and P0174 codes while driving the other day, about 20 miles after I used the CRC intake cleaner. I have a log from a few months ago where it showed my LTFT being between 0-5%.

I have tried the following to fix it:
Cleaning the intake with CRC intake cleaner
Swapping the coil packs and wires between cylinder 2 and 4
Bottle of techron fuel cleaner in the tank.
Spraying small amounts of ether around every vacuum line I can find, but no surges or changes on idle when I do it
Cleaning the MAF sensor with CRC MAF cleaner

At this point I'm not sure what the problem is. Someone said it could be an 02 sensor that got dirty after using the CRC/techron, but the o2 sensors still read as normal when I compare recent logs to past logs. Could it be a bad injector?

Mods: e85, CAI, Exhaust


I5-1 Log.hpl

[orrwhat]

I'll start off by saying I don't know a whole lot about what I am looking at in the logs that I have.

My car has a problem with misfiring when it starts cold, always cylinder 4. HPtuners shows it misfires around 80 times, and then once the idle dies down it mostly stops (This doesn't happen on this log because the car was already warm). However, when I let off the gas from light acceleration, cylinder 4 misfires twice. I have a few other cylinders that misfire a few times but I understand that is mostly normal.

I also noticed that my LTFT reads pretty high, anywhere between 15-25%. I got P0171 and P0174 codes while driving the other day, about 20 miles after I used the CRC intake cleaner. I have a log from a few months ago where it showed my LTFT being between 0-5%.

I have tried the following to fix it:
Cleaning the intake with CRC intake cleaner
Swapping the coil packs and wires between cylinder 2 and 4
Bottle of techron fuel cleaner in the tank.
Spraying small amounts of ether around every vacuum line I can find, but no surges or changes on idle when I do it
Cleaning the MAF sensor with CRC MAF cleaner

At this point I'm not sure what the problem is. Someone said it could be an 02 sensor that got dirty after using the CRC/techron, but the o2 sensors still read as normal when I compare recent logs to past logs. Could it be a bad injector?

Mods: e85, CAI, Exhaust


I5-1 Log.hpl

You might run some BG44K fuel injection cleaner through it. the GDI injectors get clogged rather quickly from carbon deposits.