So I took my 4runner in (again) to see if it would pass smog. The results were much better , but it still didn't pass bacause my hydrocarbons were too high. Here is a picture of my results.Any idea how to get these stupid things down to a reasonable number without tearing the motor apart again?Thanks

 

Fresh oil and PCV valve in the engine? If not, do so.

High HC is too much fuel or not enough air. Make sure air filter is clean. Then O2 sensor is working, it is a Denso and not a Bosch sensor, right? And if all that is OK, a new cat. will help a lot.

 

Okay, it is a brand new air filter, maybe 40 miles on it, and I already put a new cat on it. As a matter of fact, it is a Bosch o2 sensor. Does Bosch suck or something or does it give off the wrong signal?

Btw you have just given me more info than my local dealership would without me paying $90 for a diagnostic test. Thank you for at least giving me a place to start. You

 

Bosch and many other O2 sensors do not have a long enough sensing tip to get into the exhaust gas flow on the Toyota exhaust like the longer tipped Denso sensors. A real Denso sender is not that much more expensive than other brands:
http://www.sparkplugs.com/

Bosch parts work excellent on German made vehicles (that is all I use on my VW), but on Toyotas, Denso parts seem to work the best.