I was trying to check my O2 sensor and noticed a small crack in the manifold. It's leaking because on the back of the heatshield there's black stuff, not a lot though. So will I notice a difference in replacing it with a 4-2-1 header? Also how do you get the O2 sensor off? I was trying to fit a wrench in there but the A/C stuff was in my way.

 

you can try using an o2 socket. its like a regular socket but made to fit the o2 sensor and compensate for the wires.

 

a crack sucks as far as sound goes, but performance wise it is not going to make a huge difference. It may heat up the engine bay a bit, but down the road that crack will get larger and you will have to get a new manifold.

 

Hey sorry to hijack but just a quick side question. i dont wanna post a new thread... OBD1 cars have 1 sensor on the exhaust mani right? obd2 has one on the exhaust mani and cat?

 

Thanks guys. The O2 sensor socket looks cool.

 

yeah, but that is not the only difference