Yes all four of the sensors are needed by the computer. If you mean that you are having a cat back system put on then there will be no issue since their mounting bungs will still be intact.
well........yeah- get headers with those O2 portals on 'em-
The O2 sensors make sure your engine is not running to rich or too lean. Your gas mileage will suffer without them.
Does a 1997 Mercury Grand Marquis Have a Block Heater?
1997 Mercury Grand Marquis 4 Dr LS Sedan
-
General
1999 Mercury Grand Marquis with no owner manual. Radio/cassette has buttons marked cd/tape. When cd pressed display reads "no cddj". Does this button control optional cd changer. Should there be a con...
1999 Mercury Grand Marquis 4 Dr LS Sedan
-
General
Did Mercury make a Grand Marquis without air conditioning? Can I buy a short belt and bypass the compressor?
2000 Mercury Grand Marquis GS
-
General
I just bought a 2000 Grand Mercury Marquis I've change the cooling fan but it's not turning on the car is not overheating also I want to know why the fan is not turning on ?I want to know where is ...
2000 Mercury Grand Marquis LS
-
Maintenance & Repair
2000 mercury grand marquis heater hose replacement
2000 Mercury Grand Marquis LS
-
Maintenance & Repair
CarGurus has 2 nationwide Grand Marquis listings and the tools to find you a great deal.
Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use. Content will be removed if CarGurus becomes aware that it violates our policies.