My truck is running real rich and is getting 9 mpg..aahhh! Any ideas why its running rich?

 

Upstream O2 sensors are probably shot.

 

thats what i was thinking. start off with the O2 sensors then maybe clean my fuel injectors. What MPG should my truck be getting?

 

My guess is that if your running rich then your injectors are flowing fine and don't need to
be cleaned. I average 13mpg but that depends all on how you drive and where you drive.

 

I agree it's probably the pre- catalytic converter 02 sensor. That is the most common thing to go with this sort of thing. Possibly a plenum gasket leak, but you would also notice a loss in performance. Wouldn't hurt to look down the intake and see if there's any oil pooling it it though.

Also if purple dodge come on here and suggests that "maybe someone farted" feel free to slap him...

 

OH THERES LOSS IN PERFORMANCE!!! TRUST ME. So what does this mean now? Its running rich and i have loss of power. This is just Great... so where should i start looking?

 

Thats where you should start looking

 

Check and see if there's oil pooling up in your intake. Pull one of your spark plugs and see if it's oil fouled. If that's the case you'll want to be replacing your plenum gasket or buy a superior intake manifold.

Also might want to check and see if your catalytic converter is clogged.

 

When my plenum gasket finally went bad enough to require replacement, it was my #8 plug that had the heavy carbon on it, and #7 to a lesser degree. Apparently they get it worst because the oil pools in the back of the manifold due to the angle of the engine.