If my product uses pre-certified wireless modules, do I still need CE testing?

Yes. Pre-certified radio modules can simplify the radio conformity assessment under the Radio Equipment Directive, but they do not eliminate the need to evaluate the finished product. The final product must still be assessed for EMC, safety, and proper radio spectrum use in its integrated form. The enclosure, antenna configuration, grounding, power architecture, and co-located electronics can materially change compliance outcomes. Module certifications are inputs to your technical file, not a substitute for a final product conformity assessment.