06 Magnum AWD to RWD plus mods code...help needed

[NoMercyRT]

Hey guys, new to tuning and getting my feet wet by jumping into the deep end. We converted my 2006 AWD hemi magnum to rwd and when running part throttle spiritedly from a stop i get a P2174 error code. I will try and post up a log file if I can get it to do while logging. Here are the mods changes to the car so far... 6.1 headers, 6.1 midpipes and cats, open exhaust, nag1 and rear suspension from a 2014 dodge charger. I have used hp tuners to minimally tune the car so far to remove the AWD present set in the pcm and change the rear ratio form the AWD 3.07 to the RT rear end of 2.65. That rear end will change once the bugs are worked out to better gearing. the car runs like a beast but everyonce in a while when pullung out of a parking lot or leaving a stop light, If I put a lot of throttle down it will stumble and once I got a pop in the exhaust, and it goes into a limpish mode. it will still drive fine, but no third gear, delayed on movement with pedal presses but will still cruise at 60-70 in 4th. If I pull over and key off and restart it works again just fine till it happens again which can be ten minuted or two weeks. THanks for any help or pointing in any direction. I have a 6.1 intake and throttlebody I have been thinking about putting on this car if I can get it portmatched or a set of adapters, but i really want to get it more reliable to play with.

[NoMercyRT]

here is a log with a horrible stutter but no code...after stopping and saving the file it ran fine with no engine off on restart.
stuttering on accel.hpl

[NoMercyRT]

Bump for assistance. Currently the car seems to run fine, but after running fine for a while the car will bog down and stutter and sometimes die. A restart will generally fix it, but once or twice it would be a hard start and die.