02 Sensor Replacement

[Dubeckyj]

Hey all. Is there a way to take the upstream sensors out without removing the y-pipe? I live in the rust belt, and I can see some nasty things coming up dealing with the studs on the exhaust manifold.

I got under the car a few weeks ago to try it, and I couldn't seem to even get a wrench in anywhere to turn. There was definitely no room for the 02 socket & imact

Worst case, what's the book rate to get my local mechanic to bust his knuckles for me?

 

[98SF19]

Pain in the rump

I just changed out my upstreams a couple months ago and it was a PAIN. BUT, taking it to a shop, I believe the front sensor is booked at around 2 hours, which involves taking alot of stuff apart to get to it. This may be the "easier" way to do it, but I can say that I did both of them with a 6" crescent (an example of working harder, not smarter). For the front one, I kept having to go back and forth from looking from the top, then getting underneath, 1/8th of a turn at a time once it's finger tight. The kicker is that, per the opinions of folks on this forum (whom I do trust), the ones I took out seemed ok!!

 

[Dubeckyj]

My car has 160k on stock sensors. I think they're at the end of their lifetime. 2h is more than I'm willing to pay. How long did it take you to yank them yourself?

 

[98SF19]

Have you gotten the code for "catalytic converter efficiency out of tolerance" or something like that (forgot the exact code). Mine were fine as well apparently. My odie shows around 122k but the car's probably seen closer to 130k or better.

As far as swapping the two sensors, I'd say it was somewhere in the vicinity of 2 hours, maybe more all told. Much of that was spent in just sticking my hands here and there and seeing which route allowed a better angle where I needed it, ESPECIALLY the front one. There was also the whole underneath-setup of towels, lamps, tools. I did spend a bit of time trying to figure one of them out before I noticed that it was a POST-cat sensor. Derrrr!! I don't own one, but a coworker was supposed to bring me a 3" long wrench for the job, but I wound up just using my own 6" wrench. I would not do it again! I think the code I got (a few years ago) was the cat going, not the sensors. My motivation was my horrible fuel economy. New O2 didn't fix it.

 

[Dubeckyj]

Bummer. I'm hoping to fix poor economy as well. It doesn't give me a warm squishy feeling hearing it didn't help your car.

 

[98SF19]

Search my handle within the last 6 months or so and you'll find my previous post on the matter. There was some valuable information from others in there, mostly emphasizing the high likelihood that it was the MAF that was the culprit. I think I even put up some pics of my old O2 sensors.

 

[dqdude]

I was forced to replace mine and ran into the same issue, no room. I found it not very difficult removing the Y-Pipe. The most difficult task I had was accessing all the connectors and removing the sensors from the pipe. Ended up cutting the O2 sensors in half so I could get an impact socket on it. Even with PB Blaster soaking over night, it took my 1/2 inch drive impact about 5 minutes to break the old sensors loose. I did have to run a tap or "thread cleaner" to restore 2 of the ports so the new sensor would thread back in. It took me a whole 15 minutes to reinstall the Y-pipe. Total time minus the over night soaking would have been right under 2 hours for all 4 sensors.

 

[Dubeckyj]

I was forced to replace mine and ran into the same issue, no room. I found it not very difficult removing the Y-Pipe. The most difficult task I had was accessing all the connectors and removing the sensors from the pipe. Ended up cutting the O2 sensors in half so I could get an impact socket on it. Even with PB Blaster soaking over night, it took my 1/2 inch drive impact about 5 minutes to break the old sensors loose. I did have to run a tap or "thread cleaner" to restore 2 of the ports so the new sensor would thread back in. It took me a whole 15 minutes to reinstall the Y-pipe. Total time minus the over night soaking would have been right under 2 hours for all 4 sensors.

Aha, but you live in Texas. In the rust belt, I'm looking at cutting off and replacing the ****** bolts, and I have no idea what I'm going to be staring down with the exhaust manifold studs. On my SLO, I had to torch the studs, then turn them out with a pair of vice grips, and replace them with a bolt and nut. A lot less room on this car to try that, so I don't want to get into removing the pipe if I don't have to.

 

[My_Silver_SHO]

I got my O2 sensors from AutoParts123.com

Vehicle:1996, FORD, TAURUS SHO, V8-207ci 3.4L F/I Vi
2 Upstream Exact Fit Oe Type Oxygen Sensor
{two Reqd; 4 Wire; Heated; Check/replace Interval: 100,000 Miles};o-2 Sensor; Years:1996-1998; Per Car Qty:1; BOSCH 13117 $29.56 $59.12
2 Downstream Exact Fit Oe Type Oxygen Sensor
{two Reqd; 4 Wire; Heated; Check/replace Interval: 100,000 Miles};o-2 Sensor; Years:1996-1998; Per Car Qty:1; BOSCH 15717 $26.60 $53.20

Discount (SCHOOL ): $11.23
Subtotal: $101.09
Shipping - UPS Ground Residential: $0.00
Total Weight (4.0lbs. ):
Sales Tax: $0.00
Order Total: $101.09

 

[98SF19]

Only upstreams

I'm surprised to hear that you did the downstreams. You don't need those unless you've replaced your cats. Does Pennsylvania have emissions testing? Florida doesn't, and so all I'm concerned about is the MAF to upstream sensor data.

 

[Dubeckyj]

I got my O2 sensors from AutoParts123.com

Vehicle:1996, FORD, TAURUS SHO, V8-207ci 3.4L F/I Vi
2 Upstream Exact Fit Oe Type Oxygen Sensor
{two Reqd; 4 Wire; Heated; Check/replace Interval: 100,000 Miles};o-2 Sensor; Years:1996-1998; Per Car Qty:1; BOSCH 13117 $29.56 $59.12
2 Downstream Exact Fit Oe Type Oxygen Sensor
{two Reqd; 4 Wire; Heated; Check/replace Interval: 100,000 Miles};o-2 Sensor; Years:1996-1998; Per Car Qty:1; BOSCH 15717 $26.60 $53.20

Discount (SCHOOL ): $11.23
Subtotal: $101.09
Shipping - UPS Ground Residential: $0.00
Total Weight (4.0lbs. ):
Sales Tax: $0.00
Order Total: $101.09

Saying I had trouble taking the old ones out should imply I have a new set already, which I happily ordered from rockauto, though I thank you for your shameless plugging.

 

[rnddude]

I was going to start a new thread to ask the following questions, but this seemed to be in a similar vein, so here goes.

I have removed the entire engine/transmission,cradle from a 97 Gen3 to use in another project vehicle. Of course, access to all 4 O2 sensors was now easy, and they all came loose easily. What I am wanting to do is fabricate a totally new exhaust system and eliminate both of the preliminary cats. I am OK with installing new bosses in the new exhaust system and reinstalling all 4 of the sensors. The question has to do with the ECU programming, and how it interprets the O2 sensor data, especially as it relates to comparing the pre-catalist sensor vs. the post-catalist sensor data. Does anyone know how the data is interpreted by the ECU? for example, does the ECU expect to see different values pre and post cat? If the readings were the same (which would be the case in my custom exhaust) would the results ONLY be a cat fault code message, or would it impact the actual mixture and/or timing? Can the post-cat sensors simply be eliminated, or will the ECU freak out, and if so, what are the likely results. I can live with fault codes being thrown, if they are just messages. But if they impact ECU programming and engine performance, not so much so. Looking for experts on the ECU to chime in.

 

[Dubeckyj]

The downstream sensors only monitor the cats. Taking them out will throw a code, and that's all. IIRC, the code will flash at you and attempt to slap you through the steering wheel. It can be tuned out with SCT.

 

[rnddude]

Thanks, I was hoping that might be the case. A question....you posted "It can be tuned out with SCT." Ummm, forgive the dumb question, but what is "SCT"?

 

[SHOZ123]

SCT is a tuning option for the V8 SHO.