My check engine light is staying on.. The computer anylist says1. oxygen sensor defective 2. fuelm system running very rich 3. fuel pressure very high or low fuel pump or pressure regulator. Wher would you start? for the eaziest and less expensive//||??? Thanks
How do you change a oxygen sensor of Mercury Mountaineer?
Change the fuel filter first. Next, check fuel pressure to see whether it's high or low. Next, check fuel pressure regulator for having a ruptured diaphram by removing the vacuum hose from it with engine running, If fuel runs out of regulator vacuum port, replace regulator. Lastly replace the o2 sensor. You'll need to know which sensor it's saying is bad because there are 4 sensors on it%26gt;
How do you change a oxygen sensor of Mercury Mountaineer?
In your case, I don't think it is the problem with the O2 sensor. You have engine not operating properly and sending out unburned fuel out to exhaust line.
I would start by replacing the fuel pressure regulator and ignition system tune up. (spark plugs + wires). If the tuneup does not fix the check engine light problem, then replace the O2 sensor. You need a O2 sensor socket, and 25%26quot; breaker bar. There are few different type of O2 sensor socket, and using right kind for your car may make this job easier. (using the wrong type, you would run into not enough space for tool problem)
Does a mechanic have to change the oxygen sensors on a 1998 Mercury Mountaineer or can anyone do it? Also, how many oxygen sensors are there on my vehicle?
