i have a '97 SS and a week ago the ses light came on. i scanned it and gave me codes P0174 and P0430. the car is kinda running like **** and it is loosing a lot of hp. i think it might be the passenger side O2 but not sure. i was wondering if anyone else might be able to give me there opinion.

 

P0174 System too Lean (Bank 2

P0430 Catalyst System Efficiency Below Threshold (Bank 2)

 

i know what the codes or i have the camaro book, but i'm sure this could be other possible problems other than an O2

 

try replacing the o2s and see what happens, maybe the cat is clogged?

 

should i replace the o2 in front of the cat or after the cat?

 

You need to attack one problem at a time. The P0174 means the system is running lean, and the PCM can't correct for it. Could be a bad O2 sensor, but it could also be an exhaust leak, misfires, vacuum leak, etc. If you had a scanner, you could check the long term fuel corrections, to see when/where the problem is most severe, and if it is affecting both sides of the engine. That might give you a clue to the source of the problem.

Another approach is to switch the left and right side pre-cat sensors. If the problem follows the sensor, it is a sensor problem. If the problem stays on the passenger side, it is something besides the sensor.

If the A/F is buggered up on the passenger side, the cat might be having a problem dealing with it, and that could be affecting the readings form the after-cat sensor on that side. Fix the "lean" condition first, then see what happens with the after-cat sensor/cat effciency problem.