LTFT's running lean.

[txarkitekt]

I thought the same as others mentioned above. It's a lot easier to put a torch on a stuck O2 Sensor than it is to drill a hole and weld in a new bung. Have you checked your Freeze Frames? Try to duplicate the conditions recorded by the Freeze Frame data and then monitor the PIDs that effect fuel control. Have you tried to determine why only one bank is LEAN? Exhaust leaks can cause you to go lean as easily as intake leaks. Have you tried to watch your STFTs while you spray bank1(starter fluid, propane, brake kleen). Your STFTs will react quicker than your idle speed. Remember LEAN doesn't always mean too much air. The stioch ratio is 14.7:1. What if your problem is fuel starvation instead excess air because of the more common vacuum leak? You're LEAN either way.

SPOT ON.

I was helping him work on the truck and the plugs were black as night. The only things I can think of are exhaust leak(we fixed that issue), bad O2 sensor, or something in the tune that doesn't jive with what the sensors are reading.

Did you guys get that header bolt in the head taken out?

do you have an exhaust leak on driverside? say a broken header bolt? possibly a bad intake gasket on the driverside

He did. Not sure if it was able to be taken out... Bob said he checked the intake for leaks and came up with nothing.


Since no conclusion has been conceived by now, you are going to have toi go back to the old school way of reading the motor by looking at the plugs. They're black as night huh? Well right there, we know the motor is fueling more than needed. Bob said it is much as ~22% on Bank 1 at idle. The PCM is obviously detecting a lean condition somewhere...or (depending on the condition and settings of the MAF) since we are experiencing colder temps (colder air is more dense, requiring more fuel) the PCM is figuring out it needs a tad bit more fuel and it is compensating.

To get this issue resolved, a scan file needs to be sent to your tuner along with all of the things you have done to help remediate this (cleaned MAF, fixed header leak, changed plugs, etc). He can tell you more about what is going on Real Time than you can...