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Ron, ASE Certified Technician
Category: Ford
Satisfied Customers: 35614
Experience:  23 years with Ford specializing in drivability and electrical and AC. Ford certs and ASE Certs
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1997 Mercury Sable: shakes..exhaust..Rev it up a few smooth

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1997 Mercury Sable-If catalytic converters are bad will this cause the car to start hard. Most time you have to push gas to get it started and once started it shakes and sounds plugged up with strong exhaust smell. Rev it up a few times and it smooth out. no problem driving down road


When the catalytic converters go bad they can cause a hard start and a noticeable loss of power. Restricted converters will also make the exhaust sound plugged. This can effect the amount vacuum that the engine requires to run properly because of the excessive back pressure in the exhaust system.

Customer: replied 9 years ago.
It seems to have all the power while driving. I did check the plugs and 3 were dark and 3 were much lighter color. Is this normal?
No they should all be light in color, the dark would indacate a rich condiation. Is the check engine light coming on?
A simple test you can do to determine if it is in fact plugged converters is to loosen the exhaust on both banks. If it runs right then its likely restricted cats.
Customer: replied 9 years ago.
this is the code when it comes on

catalyst efficiency below threshold bank 2
Yes this would indacate a restricted cat, Are the dark colored plugs on bank 2?
Customer: replied 9 years ago.
2 in back and one in front but they are all on the corners
Well like I said, loosen the exhaust pipes where they hook on to the manifolds and if there restricted , you should notice it run much better.
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