1997 Buick Park Avenue Ultra 3.8L SC with code P0171

Question

Hi Reynaldo

Yes, scan tool got live data. But I don't know whether I can freez the data or not.

Thanks again

Answer 1

By disconnecting the MAF the vehicle went rich, If P0171 is not there the live data is all you need, The only data you need is fuel trim. On the live data is short trim bank 1 and long trim bank 1 this represent the the cylinder where number 1 is located bank 2 is where cylinder 2 is located and on the data you will have short trim bank2 and long trim bank 2. The fuel trim is all you need. Think of fuel trim as money If the trim is close to zero it means it uses all the fuel (that what it has to do) For example short trim bank1 is +5 and long trim bank 1 is +8,this both these number added up is +13,This mean you have 13% fuel not being used but is getting dumped,But if you have short trim bank1   is a +5 and long trimbank 1 is a -8,add together you get 3 or -3,because it is close to 0 and not over 10, your in fuel control, Clear codes put any disconnected sensor together,drive the vehicle but watch the fuel trim, for bank1 (you can use bank2) but short and long trim bank1 should not when added together go over +10, if it does it codes up,P0171, Compare the data with MAF connected and MAF disconnected. and what do you get?