O2 sensors for 98 SOHC

[aldive]

The following thread details an O2 sensor problem that I experienced: Dead Link Removed

 

[Spas]

Wow, Aldive..you sure had a heck of a time with yours!! Glad mine didn't do all that (yet)...

I bugged the service manager at a Ford dealer today that I was picking up a vehicle from-There is indeed an 8 year/80,000 mile exhaust warranty, transferable to the next owner-but it's only on the catalytic converters
Still, good to know if it turns out to be one of my cats!

I climbed underneath again today, looking for the sensors..can anybody post a pic of their relative location so I know where to look? (Too broke to afford a Chilton's right now ) Thanks!

 

[Spas]

Well, played detective today and got a diagnostic done....

HO2S-11=PO171 & PO172
HO2S-21=PO174 & PO174 ( I think thats supposed to be 173 & 74...I may have messed up)

That's Heated oxygen sensor bank 1, #1 and
Heated Oxygen sensor bank 2, #1, right? They're both in FRONT of the cats, I think..the ones I had replaced were BEHIND the cats...

I'm glad I read your thread, Aldive- "Security system/theft" came up as well, along with a whole host of theoretical reasons why the engine is running lean/blowing O2 sensors.

I have a gut feeling that the IAC's what caused the blow outs...You're supposed to be able to open and close it (thanks again for the cleaning tips, 410fortune!)...and I couldn't get mine to open much at all!


Anybody got a thread or info detailing o2 replacement w/ pictures?? THANKS!

 

[Robert]

Just a P0171 & P0174 I would suspect the lower intake manifold o-rings if yours is a SOHC. Those are the two codes I had when mine went out. They are also two of the codes that Ford lists in their TSB for failed o-rings. They are not necessarily an indication of a bad O2 sensor. They are not tied to your O2 sensors. The codes only mean that a lean condition was detected. There are O2 specific codes, but these are not them. A bad O2 sensor can cause these codes, however other codes should accompany them. It looks like you got a P0171, P0172, P0174 and some unknown code (P0173 doesn't exist). The description for the codes is:

P0171 - System Too Lean (Bank 1)
P0172 - System Too Rich (Bank 1)
P0173 - Doesn't exist
P0174 - System Too Lean (Bank 2)
P0175 - System Too Rich (Bank 2)

If these are the four codes you got, then it is pretty odd that your system is saying you are running both lean and rich. It would be very unlikely for both front O2 sensors to fail in the same mode that would cause these codes. I think you have other problems besides bad O2 sensors. I don't know if a bad catalytic converter would cause these or not though. I know that there are specific codes for low catalyts efficiency.

 

[Spas]

Hmm... interesting points, Robert. Lower intake manifold O-Rings, huh? Is there any way to tell for certain? A pressure test maybe? I shudder to think how much this would cost to fix if it is the problem....they're kinda hard to get to, aren't they?

Sorry about the botched codes...my mechanic was scrolling through them so fast that I had a hard time trying to read them, but I definitely did see Bank 1 and Bank 2 running lean.

Thanks again for the info

 

[Robert]

If it is the lower intake manifold o-rings, then they are covered by Ford for 72K miles as part of ONP 00M12. Do a search on 00M12 for more information on it. To tell if yours are leaking, you need to introduce propane to your manifold while monitoring your short term fuel trims. If you see a sudden change while removing and adding the propane it is a sign that you have a leak. I used an $11 Walmart propane torch to diagnose mine.

If you are over the 72K limit, then the kit runs about $50. Do a search for Mikeh. He just replaced his since his was over the mileage limit. I think he said it took him about 6 hours the first time. Ford allows about 2 hours to do it so with practice you'll get quicker. Hopefully you won't need the practice

 

[Spas]

Oh, mannn! My truck just hit 74K miles!! D'OH!

50 bux, eh? That's considerably less then I was dreading I don't know about using a propane torch, though , plus I have no equipment to monitor such things

Thanks for the info-now let me see if I can fix the problem!

 

[mikeh]

Not sure if Spas problem is the O-rings or not. If he goes over and reads my posts on the subject he should be able to figure out if his problem is related.

Ask if you have any questions.

mikeh