P1131 = Lack of HO2S11 switch - sensor indicates lean, ( upstream heated oxygen sensor )
This oxygen sensor is located before the catalytic converter, ( refered to as UPSTREAM )
P1151 = Lack of HO2S21 switch - sensor indicates lean, ( could be up, or downstream heated oxygen sensor ) " Downstream ", meaning after the catalytic converter.
PO174 = System too lean, ( bank 2 ) The fuel/air mix ratio is bad.
These DCT codes are generally caused by a problem with the emissions system. The following items are a few of the most common items to trigger those codes.
1. Dirty air filter. ( very common )
2. Faulty idle air control valve. ( common )
3. MAF, ( mass air flow ), sensor. ( very common )
All 3 of the above can prevent the onboard computer from determining the proper fuel/air mix ratio.
The oxygen sensors measure to insure the fuel/air mix produces maximum power with minimal emissions.
I hope this helps you.
Feel free to contact me in the comment section if you have a question.
Feb 15, 2011 |
2002 Ford F150 Regular Cab