Just a reminder that oxygen sensors are a wear item, and they slow down and become less sensitive as they age. Oxygen sensors are more or less "binary" devices, meaning they generally only report rich or lean, and nothing in between. If the engine is rich, they output ~1v, if it's lean, they output ~0v. So the computer will slightly nudge the air-fuel ratio around and keep the sensor bouncing between 0 and 1v. As sensors age, they respond more slowly and their maximum voltage starts to drop. Generally the computers will accept anything over 0.5v or so as "rich" and anything below that as lean.
Since I got my 62 back on the road, it ran well enough out on the road, but it was hard on fuel (harder than a 62 already is), the exhaust would stink a bit, and the idle was not particularly smooth. I wouldn't call the idle "rough", but it was bit uneven and "rumbly". Very recently I started getting some intermittent check engine lights with Code 21, which is just some generic code for "issue with the #1 oxygen sensor"
I confirmed all the wiring, and then stuck a multimeter between "OX1" (this is a direct connection to the oxygen sensor's signal wire) on the test connector and battery ground with the engine warmed up. I found that the #1 sensor really struggled to get much over 0.35v, and generally it would just stick there at idle. That means the sensor is trying to report a rich condition, but it's no longer capable of generating the requisite 1v. The computer will just keep adding more and more fuel trying to get it over the threshold, but it won't happen.
I checked OX2, and it was switching, but it was switching slowly, and the voltage was only getting up to a little over 0.5v or so.
So I hopped on rockauto, ordererd two new denso sensors for about $100 shipped and installed them. Immediately, I noticed the idle was significantly smoother. That "rumbly-ness" was completely gone, and the engine settled into a very smooth and consistent idle once it warmed a bit. When checking with a multi-meter, both OX1 and OX2 were now rapidly switching, with the voltage peaks being closer to 1v, instead of just hovering around 0.5 (or less).
So if you still have your original sensors, or they have 150k+ miles on them, you should probably consider replacing them.
Since I got my 62 back on the road, it ran well enough out on the road, but it was hard on fuel (harder than a 62 already is), the exhaust would stink a bit, and the idle was not particularly smooth. I wouldn't call the idle "rough", but it was bit uneven and "rumbly". Very recently I started getting some intermittent check engine lights with Code 21, which is just some generic code for "issue with the #1 oxygen sensor"
I confirmed all the wiring, and then stuck a multimeter between "OX1" (this is a direct connection to the oxygen sensor's signal wire) on the test connector and battery ground with the engine warmed up. I found that the #1 sensor really struggled to get much over 0.35v, and generally it would just stick there at idle. That means the sensor is trying to report a rich condition, but it's no longer capable of generating the requisite 1v. The computer will just keep adding more and more fuel trying to get it over the threshold, but it won't happen.
I checked OX2, and it was switching, but it was switching slowly, and the voltage was only getting up to a little over 0.5v or so.
So I hopped on rockauto, ordererd two new denso sensors for about $100 shipped and installed them. Immediately, I noticed the idle was significantly smoother. That "rumbly-ness" was completely gone, and the engine settled into a very smooth and consistent idle once it warmed a bit. When checking with a multi-meter, both OX1 and OX2 were now rapidly switching, with the voltage peaks being closer to 1v, instead of just hovering around 0.5 (or less).
So if you still have your original sensors, or they have 150k+ miles on them, you should probably consider replacing them.