Downstream O2 Sensor Replacement

[mcm51]

Just want to let members know what they are looking at on a downstream O2 replacement....First a little history on my O2's, when my 4.6 hit 100K I swapped all 4 O2's cause at 100K they did their job up to that point and anyone that knows me, knows that I don't wait around on sensor failure.. Swapped the both upstream's with Bosch(passenger side was a real *itch, driver's side upstream is a breeze) bettter have a helper on that one or eat your Wheaties.. Swapped my downstream's with Motorcraft DY-1081's.. My records show downstream's were done about 4 1/2 years ago BUT got a 141 and a 161 DTC about a month ago on passenger side downstream..
NOW to why I'm posting, you do not need any fancy O2 socket to get a downstream in and out, it's an easy reach with a 7/8 open end wrench, just remember that O2 has a compression ring between the threads and O2 so don't be afraid to lay into it a little bit but don't get crazy though, That's The Easy Part, The Toughest Part, get this, the O2 sensor has a quick release plug-in, which is very helpful, IF, you can get a nice and skinny hand up and in there to hold that release down while your trying to get it un-plugged and remember, Ford gives no more line that needed(which is fine, don't want any loose line flopping around that exhaust, BUT that far from help's getting it un-plugged..
SO, most of my time was spent on trying to figure out a way of getting my skinny hand(I'm 5'5" and 135lbs) up in that tight quarters and un-plug....Never thought on maybe coming down from the top, maybe thats the way I did it before don't remember.....Just have a small hand ready when working from the bottom................

[Alan H. Tast]

Thanks for posting this. While not a lot of people here are into MN12s having hands-on anecdotes like this are very helpful to more people than you may realize.

[mcm51]

Thanks Alan, that's why I post all that I do to my T-bird, I know there's a lot of people out there that would have trouble changing a spark and that's not a problem...But to me knowledge is power in the auto world and for the last 50 years I've always wanted people to enjoy their Ford's as much as I do and many cannot enjoy the older Ford's that they want to because they don't have the knowledge to fix them OR can't trust anyone out there to work on them without bringing the car home with another problem....with that in mind, As a fifty year Ford man, I could always tell how much one knows about auto's by talking to them for a few minutes....and bad mechanic's know this too !!
SO, if you gotta take your Ford in somewhere, the more you know about what your talking about, the less maybe you'll get taken....
My 50 year Ford knowledge is Free to anyone that ask's, I've never pulled any punches to other Ford Owners, I'll tell you like it is...My details of all my MN12 work as posted is to try to show that this is not rocket science and I hate all mechanic's out there that treat it as such and is in it to take hard-earned money from people just trying to keep their old Ford running nice...I'm lucky, my dad was a pure Ford man, thank God, and while he was alive, he taught me all he knew....But if any member needs any advice or info on any MN12, please feel free to ask, I'll let you know all I know about the matter...I'm almost 65 y/o and when I die all that 50 year Ford knowledge sadly goes with me...In the mean while I want to continue with the detailed postings that I have been, because this is the first T-bird Club that I really feel that my T-bird and I have a real home....Thank You Vintage International for being here AND I will always give my full member support !!!

[mcm51]

**Update** When you get a DTC 141 or 161, get on it, my 4.6L loves that new downstream O2 on the pass. side... I can tell a difference, I got my nice smooth idle back, my normal mileage and back to that sweet tone at highway speed...
I run with those codes for about a month before I could get to that swap out and this is what it was doing to me...First off I did notice it mainly on a rougher idle ( made me check my records as to when I last installed plugs and wires) turned out about 40k ago, and if you watch your mileage, I could tell I lost about 3 mpg on the highway AND of coarse my felt a little doggy at lower R.P.M.'s......
Now my Bird is back to running like a top again... Any members feeling any I these issues in there 4.6L, watch those codes....

OH, that failed downstream that I had replaced, had roughly 5 years and no more than 20K on it...I rarely see Motorcraft parts give out that soon....

[mcm51]

**UPDATE** My 4.6 is running super, it has a great exhaust tone at highway speed....Got my m.p.g. back, highway mileage is as follows, cruising at 60 m.p.h., 28 on 87 non-ethanol, 30 on 93 non-ethanol, compared to 24.5 on a good day, with a tail wind, using Shell 92 ethanol(grain alcohol) and this is all without help from a working emission system that would advance my timing on the highway and get even better mileage. .........BTW, I stopped using moonshine, oops grain alcohol, oops I mean ethanol spiked fuels many years ago.....

[mcm51]

**CORRECTION** That's 26 m.p.g. on 87 octane non ethanol NOT 28........Currently I've been running 90 octane non-ethanol the last couple of tanks (been wanting to stay between 90 and 91 octane, my Bird seems to like this rating the best) and just recorded 29 m.p.g. on a short 100 mile trip I made yesterday, just me in the car, all highway miles, 90% flat roads...............