Acceleration Slow, RPM Drops

i got a question? i recently bought my riviera...about a year ago for 500$ (needed a motor). i replaced the motor and it drove fine at first maybe a couple weeks or so and then it started driving weak. the acceleration is slow and the rpms drop when accelerating. when i get to about 50mph the rpms go from about 2000 to 1500. and also i think the manifold is wrong on it the OEM o2 sensor doesnt fit into the grooves it seems to big. and th o2 sensor isnt plugged up neither to the harness. somebody please help me out!!!!

oh and when i try to accelerate...the car shakes and its definitely nothing with the steering it feels like it comes from the engine itself...is it the motor mounts? transmission fluid is good and it leaks nothing but a lil oil very lil

Riviboi95 wrote:

oh and when i try to accelerate...the car shakes and its definitely nothing with the steering it feels like it comes from the engine itself...is it the motor mounts? transmission fluid is good and it leaks nothing but a lil oil very lil

Wrong thread to post this in dude
Maybe AA can be nice enough to move it for 'ya

Anyway, you mentioned the O2 isn't plugged in, and/or doesn't fit into the manifold? You need to fix that problem ASAP man. Without the O2, the car will run like bawlz.