2002 explorer p0175 code

I have a 2002 explorer with 72k miles. My CEL came on a few months ago and I'm trying to diagnose the problem. I know that the p0175 code means system rich bank 2. The clerk at Auto Zone told me I should change me oxygen sensors. There are 4 of them. 2 sensors before the catalytic converter and 2 after it. Does anyone know it I'm headed in the right direction? Do I have to change all 4 sensors or can I change just one? I was wondering if the 2 before the catalytic were for left bank and right bank, and the same with the 2 after. Is it also possible that my spark plugs need to be changed. The manual suggests doing that at 100k. Any help would be apprectiated.

Welcome to the forum!

Starting with O2 sensors would not be a logical step for this diagnostic code.

For a code P0175, the factory service manual suggests checking the following:
For lean and rich DTCs:
Fuel system:
-Excessive fuel pressure.
-Leaking/contaminated fuel injectors.
-Leaking fuel pressure regulator.
-Low fuel pressure or running out of fuel.
-Vapor recovery system.
Induction system:
-Air leaks after the MAF.
-Vacuum Leaks.
-PCV system.
-Improperly seated engine oil dipstick.
EGR system:
-Leaking gasket.
-Stuck EGR valve.
-Leaking diaphragm or EVR.
Base Engine:
-Oil overfill.
-Cam timing.
-Cylinder compression.
-Exhaust leaks before or near the HO2Ss.

-Rod

Wow! That seems like alot of things to check. I know that I put a bottle of Sea Foam in about a month ago. I thought that might help clean the fuel injectors. I guess I could put in a new PCV valve. Also check the oil dipstick. Outside of that, what order should I attack those issues? I just bought a Haynes manual and maybe I could find out where and how to check the other things.

The PCV valve is considered a routine maintenance item, so replacing it would not be a wasted effort. The oil level and dipstick is simple to check, so that is also a quicky to look at early. Also check the air filter for restrictions.

I'd probably start by checking the fuel pressure at the fuel rail. You can purchase a fuel pressure guage, or possibly borrow one from your local auto parts store. Make sure it has the Ford adapter (which most do these days).

If the fuel pressure is within spec, then I'd check the MAF sensor and carefully clean the sensor elements with electrical parts cleaner.

It is fairly common for the EGR system to have issues, either due to carbon build-up in the valve and/or passages, or due to a faulty DPFE sensor. I don't recall if the DPFE is much of an issue in the 2002 model year though. If you can remove the EGR valve without feeling like the fitting and bolts are going to break, that would be another good item to check. If it looks to be pretty carboned up, some STP throttle body cleaner may work well to clean it.

I don't think cracked exhaust manifolds have been a concern on the 2002 either, but that would be something to look for and listen for as well.

Other then the CEL coming on, does the engine start easily and idle smoothly?

-Rod

The car does start ok. I have had random issues of it not starting. Like once every 4 or 5 months, it cranks and cranks but wont start. Then after I let it sit for a couple minutes it starts up fine. I don't know if that is related or not. But it does idle kinda rough and I notice it when I'm driving the motor seems to miss or run rough. I haven't noticed much of a change in gas mileage. Thanks for your help.

Lee

The symptoms in your last post could most certainly be related to the code P0175. It sounds like your fuel pump could be getting weak or there is a restriction in the fuel line.

When was the last time the fuel filter was replaced? This is a routine maintenance item and could contribute to all your above symptoms. If that was done recently, then check the fuel pressure at the fuel rail. For this you will need a fuel pressure guage and the Ford adapter. Most newer gauges will come with the necessary adapter.

If you want to check the fuel pressure yourself, you can purchase the gauge for under $20 or possibly even borrow one from your local auto parts store.

-Rod

When I first noticed the CEL, I poured a bottle of SeaFoam in the gas tank. Then I changed the Fuel Filter. I think I tried to buy a PCV Valve at Auto Zone and they said they didn't carry it. I also put in a new air filter. I guess I'll find the PCV valve and look into checking the fuel pressure. I let you know if I have any luck. Your help is very appreciated!

As stated before, there are a llot of possibilities to why the PCM set the code. I would strongly suggest going to a reputable ford dealer and have them put it on the computer. using their tool, they can analize the systems, watching fuel trims, maf pressure, O2 switching, EGR fuctions( even force the EGR to open and close to tell you wether or not your ports are restricted. Most times if your EGR ports are restricted you'll get a code for inseffiecient EGR flow, this is sensed by the PFE sensor in parrelell with your EGR tube. I know that allot of dealers are not very well trusted. But for 29-60 dollars you can find out what is wrong and either fix it yourself or have them do it. This code is a common code among FORDS, a service tech that knows what he/she is doing should be able to properly diagnose and fix your problem. Also I HIGHLY recommend using FORD parts. Aftermarket items, I have found, at times are just cheap junk!