Map sensor could cause rich fuel mixture too.
http://en.wikipedia.org/wiki/MAP_sensor
Dave

 

I think the map sensor is good because when I rev the motor the map valves change.
I will change back to the 195 stat and get a new o2 sensor. I will change one at a time to see if either of them is my problem.
Thanks for all the suggestions.

 

Not having a cat will also cause you to fail emissions testing.

 

Not on that scale. The 6mpg is a sure indication he is running excessively rich.

I have had many vehicles that properly tuned, didn't need a cat to pass emissions.

 

I ve put in a new gates 195 stat. I will post here if this helps.
Plugging into the pcm the o2 sensor seems to be running more lean than rich unlike with the 180.