my 156 has a very erratic idle speed, sometimes it's ok but other times it's jumping between about 300 and 1800rpm. Had it to local alfa specialist who replaced lamda probe at cost of £140, prob seemed ok for while, then returned. Garage then told me it was air mass meter and would be another £140, luckily they didn't have one in stock cause i found one for £35.00 on e-bay (new). fitted it at weekend and it's made a big difference to top end power but idle prob is back worse than ever. Any suggestions please.