I own a diag tool that is reading P1131, P1151, P0171, P0174. The 31 and 51 codes indicate "lack of Ho2s11 and Ho2s21 switches-sensor indicates lean", according to my diags.
I have changed both bank 1 and bank 2 upstream sensors, and I have changed the MAF.
The car will not idle properly. It will surge when first started and when sitting at a red light.
I clear the codes but continually get lean mixtures turning the check engine light back on.
Where I should look next?
have the same problem?
Sunday, April 5th, 2009 AT 8:23 AM