MTBGUY said:
My universals did not work as well as planned-they bolted in (screwed in ) to an adapter plate that then bolted to the two-hole flange. It looked like they would work.
Worked for around 200 miles then set of code PO420 again. Its time to call C-dan for the real thing.
A couple of comments on O2's, then y'all can do what you want. First, lets be clear that for this list, we are speaking of narrow range 02 sensors (1, 3, 4 wire depending on year of 80). They all operate on the same voltage .1-.9v. They all use the same construction. The only difference between O2 sensors is the sampling tip (hole design and depth of probe) and harness connectors.
The singe wire O2 (pre 1986) used exhaust heat to light up and the O2 wouldn't go closed loop until the computer sensed a voltage.
The 3/4 wire O2's added a heating element to reduce the time to closed loop operation. The difference between the 3 and 4 wire is that the 4 wire adds an aux ground for the sensor itself.
Any of the above are interchangeable with any of the above. You can put in a 1 wire where a 4 wire is, or a 4 wire where a 1 wire is, since the signal voltage is identical between all the versions.
Univeral vs spec O2 sensors. Universal sensors allow you to buy just the sensor element and a small harness lead, you do the splicing. It's the harness that makes an O2 specific (and expensive) to a given application. What gives them a bad rap IME, is bad connections and an improper sampling tip. That's also why the EPA has taken the "universals aren't legal" stance on them.
That said, I've interchanged O2 sensors dozens of times with great success, street or track. Where I see the failures (usually) is using a normally aspirated 02 in a forced induction engine. The sampling rate and tip depth is usually more open and deeper on a N/A car than a turbo. Turbo/supercharged cars tend to use more obstruction at the tip to get an accurate sampling rate = more exhaust pressure.
I've seen these threads here and plenty of other places. Not comparing exactly what Scott M did/bought, I can't comment on his readings. I can say that anyone using a supercharger (you too Dan!) should consider a different O2 sensor. What affects/effects O2 performance is deposits/contamination on the tip, or too much/little exposed surface area (wrong sampling rate) so the computer gets a bad reading.
You can certainly use a stock replacement part and I recommend it if you don't have good wire crimping ability. But these threads are coming to the wrong conclusion that there is only 1 O2 sensor that's 'best' for the 80. That is only an opinion, not based on how O2 sensors work, their differences, and the reality that several O2 sensors can work the same or better than what Toyota delivered from the factory.
Soapbox off
Scott Justusson
