okay ive been researching and everything but i cant seem to find what the problem is..

its throwing a po171 code, and i figured it was a o2 sensor.. but when i went and tried to change the o2 sensor and when i took a look under the car to find the o2 sensors i found that i dont have any... i have dc headers and it looks like a new catalytic converter and resonator and no o2 sensor... my headers have a crack in it where the pipe starts to turn to the back of the car.

i really need help...

any info appreciated..

sorry if its a repost!

 

What year/engine?

You must have O2 sensors to throw code P0171, which is almost surely caused by the exhaust leak.

 

2000 si.. b16a2 with around 105k miles...

but i dont believe i have any o2 sensors...

 

You would need to crawl under your car with the front end on stands to see the two O2 sensors:

 

thanks for the diagram! im going to look under my car again tomorow to see if they are in this place..

ill take some pics while im under there just incase i cant find them.. maybe it will help.

 

Fix the exhaust leak and P0171 will likely go away. Do this soon as the leak is most surely making the engine run rich, which has the potential to kill the cat.