EGR Valve removal help and 02 sensor locations?

[Mxrobins]

Hello all, new to the forum so bear with me please.
I have 2 questions:
1.] Is there a trick to removing an EGR Valve? I spent 2 hours trying to loosen the nut into the exhaust line and couldn't get it to budge. Should I try while engine is still warm/ hot?
2.]
I'm not sure how many 02 sensors it has, I can find 3 but a little bird told me it has 4.
For the life of me I cannot find the fourth.
Any help is much appreciated.
2000 Explorer 4.0 V6 XLS.
Thank you

 

[lobo411]

Try PB Blaster, maybe when the engine's still a little warm but not red hot. Let it soak in and cool down, then repeat a couple of times on the theory that the heating/cooling cycles will encourage the lubricant to penetrate the threads.

Couldn't hurt to try loosening the bolt when the engine is hot/warm, but ideally you would put a torch on the bolt housing (not the bolt itself). You want to get the thread side of the valve housing to expand, while the bolt stays small because it's cold.

The 4.0 OHV only has 3 o2 sensors. Two between the cat and the engine (one for each bank), and one between the cat and the muffler.

 

[bluestream1]

This may help for the OHV O2s

 

[Runnin'OnEmpty]

Mxrobins, are you trying to gain access to remove the
driver's side valve cover? If so, you only need to remove
the EGR pipe, which is held onto the valve with 2 bolts
plus another bolt shared with the oil dipstick tube.

 

[D.R.Ball]

Off road or on road use...It's better to ask how to fix something than having to have your car smashed by the FED's. And no if you have done a search you know the FED's have smashed a gray market MINI but they can do the same to you......Remember it's a Federal standard not a state standard.

 

[Mxrobins]

Thanx for the info/ideas guys. Already tried the KB blaster route, still cannot budge the retaining nut. Will prob take it to a mechanic....not sure what else to do? Really need to change it out.
Kinda embarrasing.

 

[pcam13]

Thanx for the info/ideas guys. Already tried the KB blaster route, still cannot budge the retaining nut. Will prob take it to a mechanic....not sure what else to do? Really need to change it out.
Kinda embarrasing.

Oxy torch heat it red hot spray copious amounts of rust blaster on it. #2 try red hot again with the oxy torch and dump ice cold water just around the nut. If the pipe breaks it had to be replaced anyways.

 

[Runnin'OnEmpty]

Another trick is to heat the nut, and touch the threads
with a candle end, letting the wax wick into the threads.
The nut will then loosen as if by magic...

 

[wheelguner]

I am a retired mechanical designer and worked in some of the nastiest plant environments to be found, such as paper mills, plywood plants, coal fired power plants and the worst cement plants. A lot of what I designed was equipment to upgrade and modernize existing plants. I made frequent site visits during tear down and then construction/installation of my designs. One of the things I learned was all of the maintenance crews in ALL of those different facilities used the same product to aid in breaking the rusty, corroded fasteners. Kroil Oil. I am also a gunsmith and the majority of the shops I have visited have Kroil on their work benches. I have never found a product that will penetrate like this stuff.
Here is a link to their website:
http://www.kanolabs.com/google/