I just finished putting on long tubes, and shortly into my test drive the cel came on, read the code and got p0174, lean bank 2. I didn't touch anything on the intake side, what could I have done to get this code? I also put in new plugs, stock replacements.

The one thing that sticks on my mind is the passenger 02 sensor bung is pretty deep on these headers, and the tip of the 02 sensor was not sticking into the exhaust stream, as it was still up in the bung. The bottom of the sensor tip was just flush with the collector. Could this be causing my problem? Same side as the code. I appreciate any help you guys could offer me, I'm worried about running it lean for any amount of time.

 

did you get a retune....? also do you still have cats?

 

This code is generated when the O2 voltage does not rise above .450VDC more than 50% of the time. Any chance you damaged the O2 sensor or the wiring when installing it? If not, I suggest checking for a exhaust gasket on that side that did not seal.
If you have a scanner that reads serial data, have someone monitor that sensor while holding the RPM steady between 1500-2000. You can take the tip off a propane torch and stick a length of rubber hose over the end of the pipe (tip removed) and lie it close to the mating surface of the head and header. If the voltage rises, you have a leak.
Obviously you should do this CAUTIOUSLY, but it works.

 

I have not got a re-tune yet, hopefully getting it done soon. I don't have cats, but the rear o2s are in the y pipe and wired up. The wiring on the front sensor is okay on the bank that is throwing the code, there is always a chance I damaged the sensor, but I was careful to keep it clean and not bang it. I do not have a scanner that reads serial data, is there another way to check for exhaust leaks?

 

Truck is also starting to misfire. It isn't throwing a code, but I can hear and feel it misfiring at idle, and also sometimes under wot. It is not steady, maybe once every 2-3 seconds, sometimes not at all. I didn't have to force off any plug wires so I don't think any are damage, and plugs are new 41-110 ac delcos.