I just filled up, and I am getting 10 MPG, and I have been driving it like an old lady.and when I did the plenum, I put a Stant 195 degree thermostat in.

I just hooked up my code reader, and it told me this:



It says my coolant is 183 Degrees. Is it possible that the truck is still running in warm up mode, and the 02 sensors aernt working?

 

183* sounds normal.

But your front O2 sensor might be shot. Hughes Engines has the best price on NTK sensors I've found. $49 for NTK 23151

 

By 183 degrees the computer would have gone into closed loop and the O2 sensors would be working.

 

I know why I get such bad mpg's too. I got a 3 ton truck with a V8 engine.

 

hahaha but 10? Really?

 

Well, if that isnt the problem, I guess I will make a trip to Napa tomorrow and get a new distributer cap and rotor.

 

Did you check your cat? My mpg sucks right now and I've done the Hughes plenum, cat is most likely plugged up so I'm gutting it tomorrow.

 

was the truck fully warm when u checked it ?
if yes i would say try a new temp sensor for the computer...

 

Why do you say that?

 

I havent checked my cat because I dont know how, and because my truck has 75K miles on it. I doubt it bad.

I dont think my temp sensor is bad.

Yes, truck was fully warmed up, and it was 42 degrees outside.