Just assuming it has between 50,000 and 80,000 miles it is almost certainly the O2 sensor. Very popular after 50,000 miles and hardly ever causes any noticeable problems except maybe a slight drop in fuel economy because it will be running a little rich.
I have a 1998 Mercury that this happens to when the gas level gets below 1/4 of a tank. My brother is a mechanic and said that it's just the O2 level and it doesn't cause any harm. To reset it, just unplug the battery for about 2 minutes, then plug it back in.
I purchases a used 2000 Grand Marquis in January and my check light came on without apparent cause. I had it checked and it was a intake manifold leak. Ford has a recall on these manifolds that ends some time this month and will replace the bad manifold for free. You need to have it placed on a computer at a dealership. Ford lost a law suit about the bad intake manifold recently. .
The engine in a 1993 grand marquis is a 4.6 litre/281 cubic inch.
how to changing engine coolant on a 1993 mercury grand marquis gs.
NO belt in the 302cid engine of a 1988 Mercury Grand Marquis. it is a chain with gears
Mercury Grand Marquis was created in 1983.
At the front of the engine , towards the drivers side of the engine ( power steering fluid reservoir on a 1998 Mercury Grand Marquis )
According to the 1996 Mercury Grand Marquis Owner Guide ( 5W-30 is the PREFERRED engine oil )
Bank 2 is the drivers side of the engine in a 2000 Mercury Grand Marquis
Have the codes read.
what is the part called where the water pump is connected to on a 1996 mercury grand marquis -------------------------- That would be the engine
The firewall on your 1999 Mercury Grand Marquis is the metal wall that divides the passenger compartment from the engine compartment
The thread on cap on the engine coolant reservoir is the " radiator cap " on a 1995 Mercury Grand Marquis