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Tim's Auto Repair
Tim's Auto Repair, mechanic
Category: Mercury
Satisfied Customers: 15818
Experience:  Have owned a repair shop for 25 yrs.
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2000 mercury sable: cel codes..car idles really rough..pcv elbow

Customer Question

cel codes 0171 and 0174 also the car idles really rough when the engine is cold. i have changed the pcv elbow because it was pinched off. this is on a 2000 mercury sable . also i have sprayed carb cleaner around the upper and lower intake manifold. also cleaned the mass air flow sensor. what do i need to do to fix this?
Submitted: 6 years ago.
Category: Mercury
Expert:  Tim's Auto Repair replied 6 years ago.

hi

you need to check the fuel pressure..the fuel pump may be weak..these must have no less than..35psi at all times

thanks

 

[]

 

 

HC4

Customer: replied 6 years ago.

I put a new fuel pump in the car three weeks ago also two new strainers and fuel filter and air filter

Expert:  Tim's Auto Repair replied 6 years ago.

sorry..computer trouble here...

 

lets check the egr valve,,remove and clean it with carb cleaner

thanks

 

 

Service and Repair

REMOVAL



 

  1. Remove the EGR valve.
1Disconnect the vacuum line.
2Disconnect the EGR tube.
3Remove the EGR valve and discard the gaskets.

INSTALLATION

  1. To install, reverse the removal procedure.
    • Carefully clean all sealing surfaces and install new EGR valve gaskets.

NOTE: The EGR valve sealing surfaces are soft metal.

 

P0135 - P0171

 

 

P0171 CONT'D - P0176

 

Tim's Auto Repair, mechanic
Category: Mercury
Satisfied Customers: 15818
Experience: Have owned a repair shop for 25 yrs.
Tim's Auto Repair and other Mercury Specialists are ready to help you
Customer: replied 6 years ago.
so I cleaned out the egr but it wasnt that dirty and still rough idle .
Customer: replied 6 years ago.
sorry i didint mean to accept . im still having the problem
Expert:  Tim's Auto Repair replied 6 years ago.

ok

after you clean the egr,,,do you still get the lean codes after you have cleared it?

Customer: replied 6 years ago.

yes, also i put suction on the egr and it functions properly .

 

 

Expert:  Tim's Auto Repair replied 6 years ago.

ok

have you checked all vacuum hoses for cracks?

also.even if you do have a new fuel pump,you still need to check the fuel pressure to make sure it is right

thanks

Customer: replied 6 years ago.
i checked the fuel pressure yesterday and it had 45 psi . i ve looked all around the car checking for hose leaks but still the same issue .
Expert:  Tim's Auto Repair replied 6 years ago.

ok

i will opt out.maybe one of the other guys has an idea of what is going on here...someone will be with you shortly

Expert:  Amedee replied 6 years ago.
Hello!

New Expert here!

Chances are you are just going to have a vacuum leak or a bad mass air flow sensor. From what you are describing, it sounds like a vacuum leak is going to be your root cause of your codes. I know you said you have checked the intake gaskets, but these are extremely common ot leak on this vehicle. Try checking them on a cold start. Also, you might want ot get your intake smoked checked for leaks with a smoke machine.

If all OK, check the Barometric Pressure (BARO) Parameter Identification (PID) on DATA to see if the Mass Air Flow (MAF) sensor is out of calibration. A normal reading at sea level is 154 Hz to 160 Hz and it drops 3 Hz for every 1000' above sea level.
Customer: replied 6 years ago.
i took of the intake manifold to look at the gaskets and there is oil all around the gaskets on the inside (also its not coming from the valve cover gaskets i checked) could the pcv valve be cloged and the reason for the oil nand the p0171 and p0174 codes ?
Expert:  Amedee replied 6 years ago.
Hello!

It is possible... but not very likley.

I would smoke the intake system and check the mass air flow sensor before doing anything else.