Hawk350

The sensors that are going into the front part of the header....are they necessary? or can they be bypassed? I am taking about the sensors on top, not below the car..

Injuneer

Do you mean the "pre-cat" O2 sensors? If so, yes you need to keep them. But they aren't on top of anything... typically they are in the collectors.

Or are you possibly talking abouthe AIR connections?

Hawk350

Actually, they screw in the top of the header where the exhaust ports are...just above them....Just wonder if they are needed.

95_LT1_6SPD

I think hes talking about his egr connectoins. If you have emissions you will need them, if not its up to you. You can block them off and put a cap in the whole on the header.

SlickBlack Z

Those are most likely the fittings for the AIR system. I have all my emissions hooked up to my headers. If you dont hook them up you will get an SES light, unless you have those parameters programmed out of your car's computer.

Hawk350

Thanks....are they necessary? I dont have to pass emissions or anything, so I can just close them off right? Will this trigger an codes?

SlickBlack Z

Yes, it will probably trigger at least one code.

Injuneer

Wiil NOT set a code. He has an OBD-I 1994. All he has to do is pull the harness connector off the AIR pump, and make sure the fuse in the circuit is good = no code in OBD-I.

And to make sure you understand.... THEY ARE NOT SENSORS. They are NOT part of the EGR system. They are piping connections that allow the AIR pump to put air into the xhaust and help the cat heat up on startup. You can delete the connections with no ill effects, other that increased emissions at startup.

You can plug most headers and the stock exhaust manifolds with M22 oil drain plugs.