So I recently pulled codes noticing that my check engine light was one again..... (this truck is starting to kill me having to fix it every 5 seconds) It's a 1992 f150 xlt lariat v8 5.8L E4OD pickup.

I have:
172 heated oxygen sensor indicates lean condition, right side
173 heated oxygen sensor indicates rich condition, right side
181 adaptive fuel rich limit reach at part throttle, right side
311 thermactor air system inoperative, left side
116 coolant temperature sensor out of self-test rang
332 EGR valve opening not detected.

Would most these codes just be caused by a bad oxygen sensor? any help would be appreciated before I start replacing everything.....

 

Oxygen sensor and most likely vacuum leaks, either in the lines themselves or the vacuum reserve canister. Those are the cheapest things to try first.

 

That's what I'm thinking is going on as well. I'll check more in the morning. I'm just trying to get some ideas of what to check before I work tomorrow haha see if anyone else has any idea on what to check on before I dig into it.

 

Okay, well figured out most my oxygen sensor problems. some how the vacuum hoses going to my tin can came undone on one side and didn't realize it until after I went to take it off. Also it seams the vacuum hose going to my EGR is cracked. Anyone know where I can get replacement vacuum hoses for this because they all seam pretty old/brittle or what size ford used in the '92s?

 

5/32" rubber tubing for most of it - I found that I needed 7/32" tubing for the MAP sensor and the A/C system hookups. You will need a couple of 5/32" T's as well.

There should be a diagram under your hood for all of the vacuum lines - that and this guide should help you along:

http://www.fullsizebronco.com/forum/...es-rubber.html

 

Thanks a bunch! That forum is just what I needed! I replaced a few vacuum hoses already with some plastic ones through napa, but even they aren't quiet fitting right.

 

I'm curious...will a poorly functioning O2 sensor or small vacuum leak throw a code? I just fixed a small vacuum leak (white line to A/C blend door), so I'm guessing that the answer in small vacuum leaks is "no", but I was hoping for some more experienced opinions, especially on the O2 sensor question.

 

A bad O2 sensor usually throws a code. Vacuum leaks can be trickier but if it is bad enough (like say the vacuum reserve reservoir has a hole in it) it will usually throw a whole bunch of codes that have to to with the TAD, TAB, or EGR solenoids. The MAP sensor and fuel pressure regulator have their own dedicated vacuum lines running off of the manifold tree because they need to directly sense the vacuum created by the engine in order for it to run properly, so any leaks there will cause a problem.

So replace your vacuum lines kids.

 

I believe the white vacuum line is only active when using max ac, that's why it doesn't throw a code.