I just bought a 03 ram with the 5.7 hemi and I have been having some sort of throttle problem I bought plugs , wires , and a tps to see if anything changes but just case id like to have a little more info about the codes (p0355, p2173, p2106)
The COP (coil on plug) ignition system is what is used on most modern engines. There is an individual coil for each cylinder that is controlled by the PCM (powertrain control module).
It eliminates the need for spark plug wires by putting the coil right above the sparkplug. Two wires are dedicated to each coil. One is a battery feed usually from the power distribution center. The other wire is the coil driver circuit from the PCM. The PCM grounds/ungrounds this circuit to activate or deactivate the coil. The coil driver circuit is monitored by the PCM for faults
If an open or a short is detected in the driver circuit for coil #5, a P0355 may set. Also, depending on the vehicle, the PCM may also shut down the fuel injector to the cylinder also.
I would switch Coil # 5 with the one next to it
Then scan for codes again & if the fault code is no longer p0355 & it is now a different #, then you know that you have a bad coil
Smoke machine is the biggest waste in modern history- paying $120 bugs for someone standing there, looking at it and waiting, while behind him the fan blows a nice breeze in his neck. I prefer the good old brake disc cleaner method- takes usually 5 minutes to find a leak.
let the engine run and start spot-spraying with short pushes on components and hose ends. When you find a leak, the RPM will go up. Double check and then look at it. In 20 years out of 30 in my job, I worked on cars physically. I never needed a smoke machine- only a bottle of brake disc cleaner.