In neurodegenerative disorders, mitochondrial dysfunction and oxidative stress lead to proteostasis failure, causing Endoplasmic Reticulum (ER) stress and protein aggregation. The mitochondria-associated endoplasmic reticulum membranes (MAM) are crucial for cellular balance and is linked to Parkinson's disease due to Parkin/Pink1 dysfunction and vesicular transport issues. Recent discoveries in pink1^B9 flies have uncovered that the enhancement of PERK expression leads to improvements in dopaminergic neurons, mitochondrial morphology, and motor function. Our research is specifically dedicated to unraveling the molecular mechanisms, which remain unclear in both pink1^B9 and park¹³/+ mutants. Earlier studies reported that Parkin functions downstream of Pink1 in the shared molecular pathway of mitophagy and exhibits a comparable phenotype, our investigation is solely focused on park¹³/+ mutants. In our earlier findings, we documented that constitutive overexpression of Rab11 in the parkin mutant background reduces the mitochondrial aggregations via the facilitation of the mitophagy process. Here, this study investigates whether defective mitochondria induce ER stress in park¹³/+ flies and affect PERK, a key player in the Unfolded Protein Response. We observed reduced PERK and Rab11 expressions in park¹³/+ and Rab11 mutants. Overexpressing Rab11 in park¹³/+ mutants enhanced trafficking and reduced ER stress. In addition to this, reduced Rab11 levels led to glial cell proliferation, crowding, and neurodegeneration in park¹³/+ and Rab11 mutants. These findings highlight the neurotoxicity of ER stress from faulty mitochondria and the role of improved trafficking in mitigating ER stress in park¹³/+ mutants.