All i can say is i had a 406 turbo diesel for two years, great car never had one single problem, put 40,000 on the clock, then traded it in for a spanking new 307hdi,worst mistake i ever made.In the first 2 weeks of ownership i had it for 4 days, never went longer than 2 months between being back at dealers because something had happened to it again.Had it 2 1/2 years and 36000 mile, dumped it and lost a shed load of money too....
A lot of Peugeots' petrols are old fasioned rattly affairs. Their modern diesels are better in some cases. So it wouldn't surprise me to hear an unreliable petrol 406. And yes they're Taxi fodder, got very common so even with reasonable styling I'm still not interested in owning one.