Lol, yea, with O2's on any vehicle, after hitting the 100,000 mile mark you can get a false DTC's. Erase the code and it may not come back for months at a time. It's the deterioration, making them sensitive. The amount of deterioration depends upon exposure to rich and misfire conditions in the past. Those two conditions are extremely hard on O2 sensors and cause abnormal wear. Regardless, changing them around the 100,000 mile mark is the norm for keeping the AF's healthy and running strong.

 

I'll order the O2's, I have six MC coils to replace the parts store ones the dealer installed (two were already swapped out), and am thinking about getting a set of remanned fuel injectors, too. That would just about cover all the bases for long-interval PM. I'm debating on replacing the existing plugs, since they only have 30K on them, but will remove, inspect, and reinstall at minimum, to insure they're torqued correctly.
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Swapping all 4 O2's is the best you can do. The rears are for monitoring efficiency only BUT if they become slow to switch, that will dig into your economy. When they are slow to switch, the AF's are in limbo longer and economy can suffer. However, they last longer than the upstreams. You can usually wait until you begin to get switching (slow to switch) DTC's on those , unless your economy is terrible.

Anytime after 150,000 miles with the injectors imo. I swapped them out at 165,000 and there was a very noticeable difference. I did the coils and 02's around the same time. The truck ran great and then there was huge gap where I didn't have to touch the thing other than normal maintenance after that....like years after.

The plugs should have a tint of white to them when it's being driven as intended. That just means highway time, and not used just on Sundays for church. The white tint is a Modular thing, they are a little lean from the factory which is a all good thing all around. If the plugs are black, like it's too rich, too many short trips, high idling and lugging times.

 

So, if I replace my rear O2's maybe I'll go from 14 MPG to 24???!!!


I'm sure the plugs are fine, but at $25 for the set, they almost qualify for a "while-I'm-at-it-might-as-well..." swap.
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Much better than that starting at the top of the mountain.

 

Hey jp, I was working on my rocking chair all day and daylight got away from me. I'll get ya pics tomorrow of the box. (I'll see if I can get a decent pic tonight but it'll probably be tomorrow)

 

Oops, wrong type of folks lol

 

No worries, this isn't going to be a fast moving project. Lol

 

2100.....look what I found today. $100. 1975 Dana 60 411's.

 

Did you buy it, AK? Looks like you might have an intriguing project in the works?