best way to change the downstream O2 sensors on a 97 sport

[Gregs X]

Took my sport in to have the check engine light. They ran a full diagnostic test, used the smoke test to check for vacuum leaks, and everything was good there. He checked the voltage on all the O2 sensors, and the downstream O2s were very low. So I am looking under my sport and trying to figure out how to disconnect them, I can't reach them with my arm to disconnect them, and there's barely enough room go get a wrench in there. All advice and ideas will be appreciated
Thanks

 

[2000StreetRod]

What was the DTC?

I see that you have the SOHC V6.

What was the diagnostic trouble code (DTC) that caused "Check Engine" to illuminate?

The after cat O2 sensors measure the effectiveness of the catalytic converter. How many miles on the odometer? It may be that there's nothing wrong with the O2 sensors and your catalytic converters have failed.

Do you have a center console? If not, under the carpet where the center console would be located is a removable plate that provides access to the sensors.

 

[Gregs X]

107,000 miles, I my original codes from autozone were banks 1 and 2 are lean. Took it in to a service garage with a diagnostic machine. After checking for vacuum leaks with using the smoke method and everything checked out. He then went through the emissions equipment and said everything was ok accept that both downstream 02 sensors were out of spec with low voltage readings

 

[2000StreetRod]

Fuel pressure?

When the smoke test was done the engine was warmed up. Often the commom problem of the upper and lower intake manifold gaskets leaking only occurs at cold start.

Have you checked the fuel pressure? Low fuel pressure can result in lean codes for both banks: Ford Explorer Ranger Fuel pressure test procedure

 

[Gregs X]

yup, he checked the fuel pressure, and actually did the smoke test on cold start, well after he pulled it into the stall. He made sure I dropped it off overnight so he could check that specifically first thing in the morning, he was a ford tech for many years prior to going on his own

 

[2000StreetRod]

valuable resource

It sounds like you've found a valuable resource - your mechanic. Did he check the fuel trims with a scanner?

 

[Gregs X]

He did not say exactly, but he said a/f ratio looked good. Dam 02 sensors won't come out, soaked them in pb blaster last night and another hour today. Breaker bar won't even get them loose

 

[lobo411]

He did not say exactly, but he said a/f ratio looked good. Dam 02 sensors won't come out, soaked them in pb blaster last night and another hour today. Breaker bar won't even get them loose

You might have to drop the line and try heating the bung cherry red. I had to drop my line to get an upstream sensor out but I didn't use heat, so I ended up tearing out the bung threads. It wasn't too bad to get it fixed at an exhaust shop (weld in a new bung), but I didn't have a torch that could get the bung hot enough. At least some heat would have given me a chance in dealing with those welded-in threads.

 

[bluestream1]

Are you using wrench to try and get this loose? You may have to cut the wires to the o2 sensor, and get a 1/2 rachet on the sensor. You can use a deep socket, or cut the old sensor off and use a short socket if room is tight. The special O2 sensor sockets are good for installs, but not that good for extractions....

Also, (I think) there is a hatch on the inside under the carpet to access these sensors and their wiring from above..

 

[rb142]

^^^ This. Cutting off the wires and using a more robust socket helps. But for a really rusty sensor, an acetylene torch is just about the only way to get them out.

 

[Torqueranger]

The best way I find to work for me is too to drive the truck for a while and when you get home remove the O2 sensor while it's still hot .... Also I would look into buying a O2 thread chaser just in case which I still have yet to buy but have been lucky with extra parts lying around ...