The first-generation Peugeot 307 (Phase 1, internal code 3A/C for the sedan) marked a radical break from the 306. Voted Car of the Year 2002, it adopted a semi-high architecture favoring interior space and safety. Dynamically, it offered an exceptional comfort/road holding compromise, typical of Peugeot's expertise. However, this generation introduced a new multiplexed electronic architecture (VAN/CAN network) which proved to be a real industrial disaster during the first years of production. Electronic failures (BSI, COM2000) and problems related to new diesel emission control technologies (FAP) and transmission (dual-mass flywheel) heavily tarnished its reputation. This is a model to approach with extreme caution on the used market.
The Peugeot 307 Phase 1 is a car full of dynamic and family qualities, but it bore the brunt of multiplexing and the first generations of FAP at PSA. As an expert, I strongly advise against buying models from 2001 to 2003, which are true nests of electronic failures. If you are looking for an economical diesel, the 2.0 HDi 90 is the only truly safe choice, as it lacks a FAP and a dual-mass flywheel. The 1.6 HDi 110 is to be avoided unless the turbo, injector seals, and flywheel have been recently replaced with supporting invoices. Always prefer a late Phase 1 model (2004-2005) or opt for a significantly more reliable Phase 2 (after mid-2005).