Posted by Alan Kane on May 16, 2005, 11:16 pm, in reply to "BMW / E46/ 318/ 1999"
Hi Brian,
171 is a decimal code which is the same as p0170. It is a fuel trim code and as stated above is usually caused by the breather valve or the MAF. The pipe from the valve to beside the MAF can leak too. The breather is more common, and a lot cheaper. Drive it WOT in third and watch MAF signal. You should see 4.2v max.