someotherguy
+1y
Hey Pig,
The heated O2 is better in general, an O2 sensor has to warm up for it to read properly, so it's depending on the exhaust heat. When we do stuff like gut our cats or chop them off, and put on free flowing mufflers, you're reducing exhaust heat, so the old single wire O2's don't work as well as they used to. A heated one is the same basic sensor except with a heating element in there so it's not really depending on the exhaust.
The reading on the O2 or any other sensor won't affect your fuel pressure, that's controlled by the fuel pressure regulator in the TBI (or inside the Vortec intake, sorry, I can't remember what year truck/what engine you've got) and stays pretty much the same no matter what.
If your truck is running too rich usually it's a problem with the CTS lying to the computer that your engine is much colder than it really is. Sometimes it's the O2 sensor but usually a bad O2 can't make it run crazy rich. Fuel pressure regulator problems can be an issue too. But bottom line, if you want the computer engine to run right, it's gotta be able to get into closed loop, and it won't do that with a cold thermostat or no thermostat. If you have an infrared thermometer or can borrow/steal one, get your truck up to temp and shoot the thermostat housing to see what it's REALLY running at. Then you can pull a reading on the CTS with an ohmmeter, I have a chart around here somewhere from another forum that will show what the reading should be for a range of temperatures.
I'm no computer engine wizard, not even gonna pretend I'm a mechanic, but I have been messing with these TBI engines for probably the past 8~9 years personally and a little bit with the Vortecs too. Learned a lot and still learning.
Richard