I am suddenly getting very poor mileage in my 92 4 runner. I've done a tune up and set the timing at 11 degrees but I'm still getting about 5 miles per gallon less than usual. I've been told about it part under the manifold that may be causing this problem but can't remember what that part is any ideas out there?

 

I think that part is called "the engine."

What happened "suddenly"? What do you consider to be included in a "tune-up"? http://personal.utulsa.edu/~nathan-b...e/64tuneup.pdf

Do you have any stored codes?

 

Under the manifold----PCV valve???

 

a bad knock sensor under the manifold can cause that, it retards timing to prevent pre ignition and runs silly rich. do you have any codes? 52 is a knock sensor i believe

 

I think it's the nox, going to get codes