1997 Mercury Sable

ICEGIRL78

MEMBER
1997 MERCURY SABLE

Engine Performance problem
1997 Mercury Sable 6 cyl Front Wheel Drive 136000 miles

I have a 97 Mercury Sable GS that needs to pass smog in California by the end of this month. I have an OBD-II pocket scanner and I have ran diagnostics on the car. There were 3 codes P1131- Lack of upstream heated oxygen sensor switch-sensor indicates lean(Bank no.1) P0171- System too lean (Bank no.1) & P0174- System too lean (Bank no.2) An oxygen sensor in bank 2 detected a lean condition (too much oxygen in the exhaust). I know that all 3 of these codes is dealing with the emissions so I'm sure the car will not pass smog like this. The question I have is could you provide me with a list of steps in the order that things need to be checked and repaired? Since I will be doing the repair myself. Any help will be greatly appreciated.

1 Reply

KHLOW2008

MECHANIC
41,814 POSTS

Hi icegirl78,

Here are description of the DTC and possible causes.

DTC P1130, P1150, P1131, P1151, P1132 Or P1152: HO2S Not Switching
DTCs P1131 and P1151 indicate air/fuel ratio is correcting rich for an overly lean condition. DTCs P1132 and P1152 indicate air/fuel ratio is correcting lean for an overly rich condition. DTCs P1130 and P1150 indicate fuel system has reached maximum compensation and HO2S is not switching at the adaptive limits. Possible causes are as follows:

"� Fuel system malfunction.
"� EGR system malfunction.
"� Air intake or vacuum system leak.
"� Engine oil level too high.
"� Excessive internal engine wear.

Inspect engine for obvious defects in specified systems. Repair or replace as necessary. If no faults are found, go to next step.

41) DTC P0171, P0172, P0174 Or P0175: HO2S Not Switching
DTCs P0171 and P0174 indicate air/fuel ratio is correcting rich for an overly lean condition. DTCs P0172 and P0175 indicate air/fuel ratio is correcting lean for an overly rich condition. Possible causes are as follows:

"� Fuel system malfunction.
"� EGR system malfunction.
"� Air intake or vacuum system leak.
"� Engine oil level too high.
"� Excessive internal engine wear.

Inspect engine for obvious defects in specified systems. Repair or replace as necessary.