Legacy Starting Issues After Ignition Coil Replacement

This sounds very similar to what I experienced with my 2012 Subaru Impreza. The symptoms match almost exactly, particularly the rough running and stalling after an ignition coil replacement. In my case, the starting issue turned out to be a combination of problems. While the ignition key turned, the starter motor engagement was inconsistent. The mechanic found that the new ignition coil was actually defective from the factory and had been causing interference with the ignition system. The root problems were: Faulty replacement ignition coil, Corroded electrical connections at the starter motor, Two blown fuses in the main fuse box This was a serious issue that required immediate attention as it could have left me stranded. The defective ignition coil was damaging other electrical components each time the key turn attempted to start the engine. Based on your symptoms, especially considering the timing after the coil replacement, I strongly suspect you have a similar situation with either a defective replacement part or damaged connecting components. Would recommend having the shop check both the new ignition coil and the starter motor connections before assuming its the ignition switch itself.

Thanks for sharing that detailed experience. My Legacy had almost identical symptoms after getting work done too, including that rough idle and stalling. I had the ignition coil replaced under warranty since it was indeed faulty, plus they found some dashboard light issues tied to the electrical system. Did you remember approximately how much the repair ended up costing? And has everything been running smoothly since getting it fixed? Just want to get an idea if any other problems popped up later related to the starter motor or electrical stuff.

Since getting my Impreza fixed, all starting issues have completely disappeared. The mechanic solved the ignition switch problem by replacing the faulty ignition coil under warranty and repairing the corroded starter motor connections. The fuse replacement only cost 52€, and labor was covered since it was related to their previous work. The key turn is now smooth, and the starter motor engages perfectly every time. No more rough running or unexpected engine stalling. The electrical system has been stable for months now, with no dashboard warning lights or other related problems. The repair shop also cleaned all the electrical connections as a precaution, which probably helped prevent any future issues. Getting it fixed early was definitely the right call, these starting issues can cascade into bigger problems if left unchecked. Sounds like your Legacy is on the same path to being fully sorted with that warranty work.

Wanted to update everyone on how this turned out. Took the car in last week and the diagnosis confirmed what many here suggested. The replacement ignition coil they installed earlier was indeed defective, causing all those car electronics issues. The repair actually went smoother than expected. Shop found the faulty part was affecting the entire ignition system. Got it replaced under warranty, plus they cleaned all electrical connections around the starter motor. Total cost came to 75€ for some minor parts since most was covered. Been a week now and the engine start is perfect, no more rough running or stalling. Each key turn results in a clean start. Definitely learned my lesson about getting these starting issues checked out quickly before they cause more damage to the car ignition system. Really glad I asked here first, helped me better understand the problem before heading to the mechanic.