@jlm1948 Hi, i would recommend to increase the hotend temperature by 5C, than can help make the filament less viscous, look at the recommended printing temperature of the PLA you are using and use a temperature closer to the maximum they recommend. Are you using the 0,4 mm nozzle? Because going smaller than that can create problem with some filaments and using a bigger nozzle can help reduce pressure, but at a certain diameter you need to be sure that the hotend can heat the plastic fast enough... I hope it will help you, have a good day/night!!

@Tickforge Hi, now you have to adjust the eccentric nut on one of the wheels, look TH3D Studio video at: https://www.youtube.com/watch?v=gAJRw1X738s . When you turn the nut, the wheel is eccentric so it can more toward the aluminum extrusion.
Have a nice day/night!

@Tickforge Hi! Please check if the wheels behind the print head are all in constant contact with the aluminum extrusion, if they are not against the extrusion, you can adjust the eccentric nut until its tight ( slightly wobble the cold print head with your hand to determine the origin of loose). Dont over tight the wheels on the extrusion or they will wear out faster. If the wheels are not the problem, verify that all the crew between the print head and the carriage are tight.
I hope that solve you problem, have a good day!

@ChristinaSmith Hi! If the aluminum extrusion is straight but become at an angle when screwed in place, check if the end is cut perpendicular to the side, it might be cut at a slight angle. And if by ''rod'' you mean the leadscrew, check if the motor is screwed parallels to the Z axis aluminum extrusion, a small square is a must at that point.
I hope those tips will help you, have a good day!

@dscatala Hi! The components on the Ender-3 V2 are not compatible with 3mm filament. To make it work you would need a new extruder+ hot end system. The original mechanism is made for 1,75mm filament.
I hope i answered your question, have you a good day!

@bt101 Hi! You can look at: https://all3dp.com/2/ender-3-pro-z-offset/ for Z offset info to level you bed.
I hope it will help you solving your problem.
Have a good day!

@rfresh737 Hi! Just go to : (https://www.creality.com/download) and the 1.1.5 board is 8bits. I think what your looking for is the Ender-3 Pro_8bit_1.1.9V_TMC2208 Firmware_0814.rar.
I hope that help you... have a nice day!