just bought a real clean 1989 pickup with 99.000 miles it has no power at all, I check to codes I get code 52. will the knock sensor or bad connection cause very low power and some popping back through the intake? also I have an o2 sensor on the manifold but there is nothing to pulg it into. there is also an o2 sensor before the cat. is there two o2 sensors? or do I have a manifold off a different year toyota?

 

Yes. To prevent knock, it retards timing to a "safe" point.

 

does anyone know if there was a o2 sensor in the manifold on a 1989?

 

you shouldn't have two o2 sensors only the one on the exhaust manifold itself