There could be a number of things going wrong. Either your filament needs to be dried more or your spool is tangled up and catching (specifically in the ams unit) meaning your print head isnt getting filament fed through in certain moments. I’m thinking it’s the first issue, that you haven’t dried it long enough. And if you don’t have an ams unit with silica beads in it, it means that your petg is soaking up a lot of moisture from the humidity in your room. Which means even if you dried it out, by leaving it out in the surroundings, it acts as a sponge and soaks moisture. Moisture in your filament causes steam, steam+pressure=explosion which can cause clogs and layer misses and poor extrusion.
I’d look at the interior of the model to see what else is happening at the heights of those lines. Often an abrupt change in layer time will let part of the model cool and shrink differently. Sometimes adding an interior chamfer or fillet will ease the transition.
The small, intermittent, bulges are usually caused by slightly moist filament.