Surging Idle, delayed and hard shifts, and "jerky" throttle response in reverse
As the title states, I am experiencing multiple issues with my WK1 SRT8. I have battled this issue for the past 3 years and am to the point where something needs to be done. My jeep is a 2006 with 86k miles on it. As for aftermarket mods, it has a Volant CAI and catch can installed. The vehicle also has an aftermarket stereo system. All modifications were installed prior to me purchasing the vehicle in 2012 and these issues we'rent happening then. I do not know if the vehicle has a custom tune, but would imagine it does based on the other mods added. Since I have had it, I have had the transfer case replaced (went out at 24k miles due to tire sizes), and the ignition switch has also been replaced due to recall. Other changes have been cosmetic only
My current issues are as described in the title. Usually after "spirited" rides, my jeep will begin experiencing the high rpm/delayed shifts, and a surging idle at low rpms. The surging idle is most noticeable in park and reverse, but not in drive at stops. These symptoms get worse as time progresses until the jeep eventually begins stalling in reverse or struggles to hold rpms above 500 in park which also resulting in a stall. No codes are given during these incidents. If I disconnect my battery for a minute, then reconnect, all symptoms vanish until the next "spirited" ride. This issue also happened the last time I cleaned/recharged the CAI filter.
The last time I took it to a stealership for the issue, they stated it needed a new electronic shift module and tune based on their diagnostics, but no codes were given at the time and I wasn't buying their word without proof. This is the same dealership that stated I needed a new T Case without noticing the tire sizes were incorrect (thanks to you guys here for that insight).
Have any of you experienced this, seen anything like this on the threads, or could possibly offer some insight as to what it could be before I take it somewhere? I would greatly appreciate any advice and am willing to explore all possibilities before taking it somewhere. I do not own a tuner so I am unable to pull any logs or re-flash anything which I would imagine would make diagnostics easier, but I am hoping some of you have seen this before and can point me in the right direction. It's hard to find a knowledgeable and trustworthy mechanic in my area for these jeeps; its always one of the other but not both.