UPDATE!

I replaced the O2 sensor this afternoon. It took all of about 10 minutes to do it. Thank you for all the advice.

One thing I couldn't do: I couldn't find the place to "mount" the connector. It has a plastic compression pin, as for snapping it into a hole to mount it. The closest open hole was on the firewall, but it is too far away.

Pix are posted in photobucket.

the engine:


and the sensor:


Thanks for all the help![/url]

up behind the center of the rear valvecover is a big metal bracket with no apparent purpose. There'* an O2 sensor wire holding mounting hole in it.

**UPDATE**

Here are the early results for fuel economy before and after the O2 sensor:

I changed the sensor last Sunday, and the least tank of gas saw my Bonny turining in a 17 mpg average. After the last fill up last night, I had to make a round trip of 206 miles. I got back home from the trip, with more than half a tank left. I realize this isn't the most accurate, but it definitely is a big improvement. Generally, I have to fill up after about 265 miles on a tankfull. But after traveling 200+, to still have a half tank left is super. Also, if you have been following my other topc regarding trans woes, you know that whenever ny car warms up, the car falls out of OD, until it cools off. So for half the trip, OD worked fine, since the ambient temperature was cool (<60). On the return trip, the car fell out of OD after about 15 miles. So it was running about ~2700 RPM'*, but only going between 65-70 MPH. And I am sure I wasted gas. I take the car in to get this repared (along with the 2 failing trans mounts) on Monday.

Thanks to all who helped and gave guidance for this simple fix. It was like grabbing low-hanging fruit!

Thanks,
John

hah, last year when my o2 sensor got so bad the engine was choking and stalling, i droive down to checker auto and after driving for 45 mins to get there i took my wrench and dug right in there and got it out, MY GOD THAT WAS HOT, all of the heat transferred from the exaust manifold and into my wrench, and soon my wrench was too hot to hold....haha, my wrench was hot for 2 hours...., so anyways, follow advice, dont go squeezing your arm between an extremely hot manifold and a firewall, YOU WILL GET BURNT! hah..

UPDATE II:

(Or...That gas gauge really isn't that reliable)!

Ok, I couldn't stand not knowing the actual results of improved MPG after the O2 sensor was changed. So I went and filled 'er up, and here is what I found:

Total Miles Driven...........................221.1
Gallons Used....................................8.54
MPG............................................... .25.88

MPG Before Change (Range)........17.0 low to 21.0 best ever

OTHER INFO:

Hwy Miles in OD.............................106
Hwy Miles w/o OD.........................102
City Driving Miles..............................13

So that'* basically a 23% improvement over my best mileage previously. The only thing different was the O2 sensor change. I assume that since I was out of OD for almost 50% of the hwy miles, the mileage would have been even better. With OD, and running 70MPH, the tach sat right on 2000 RPM; when driving on the hwy w/o OD, the tach was at ~ 2700 and I was only running between 65-68 MPH. I hope that my tranny problem is a simple, non-intrusive fix - I can ill afford a rebuild right now. I will know the story on that on Monday.

If anyone needed further proof of the impact of changing an O2 sensor, here it is

Now, the spark plugs: I have not changed them in over a year, and at least 20K miles. What are the chances I can get another few MPGs out of new plugs? I would really like to know, as they look fairly simple to change: remove the crossmember over the back of the engine, then get busy!

Any comments anyone? Thanks again to all who helped me with their advice and guidance.

John

My car'* gotten about 21 MPG consistently since the day I rolled it about 6 years and 13oK ago. Nonetheless, I ordered a new sensor because of this thread. Should get here this week.

When it does, I'll check it out and comment.

Hope you guys are right.

I'm heading in for a sensor tomorrow morning. I think mine has seen better days as well. Mileage has dropped of badly.