P0171 Code - Causes, How To Diagnose and Fix

[@MrRusell86]

This is a good video but one somewhat common cause that was not addressed is the fuel injectors. I went for three years trying to figure out the P0171 code on my 2000 Corolla. LTFT was coming in at 38%. I had changed the fuel cap, PCV valve, 02 sensor, MAF sensor, air intake gasket, and ECU in addition to looking for vacuum leaks all to no avail. The fuel injectors were up next and they were found to have cracks in the casings. I applied super glue and put on fresh rings and filter baskets. I also sprayed them with MAF sensor cleaner. LTFT went from 38% to 19.5%. This is still high but this is below the threshold of P0171 triggering. I plan to put in new injectors at some point to hopefully further lower LTFT but in the interim the originals will do.

[@nyworldrl]

oil in spark plug 1 chamber will also cause this.

[@jonjon9237]

Why oil ? Could be transmisión oil ?

[@matthewdelarosa1393]

Yes

[@Cano14er]

Gonna check that right now ,thanks for the tip👍

[@aldon78]

My 08 Accord gave me this code my mechanic charged tje cranck sensor but isnstill doing the same thing and this weekend I got the check engine plus tje VSA with a ! mark also. Any ideas.

[@irek12371]

P0174 kode bmw e60 benz