if i remove all the smog stuff on my 96 Z what will it hurt and will i have to do anything to the computer?

 

it won't hurt anything, but it will lighten your car by a few pounds. You will have to have it tuned out of the cpu and buy block off plated to where it connects in the back.

 

You remove the cats - you will have to either get O2 simulators, or get the rear O2's programmed out.

You ditch the EGR system - you'll have to get some blockoff plates for the EGR valve and the tube that goes between the riders manifold and intake. Made mine out of some light steel. I don't think you'll throw any codes so long as you leave the EGR vacuum solenoid in place and electrically connected. Just disconnect the vacuum lines from it and plug them. Getting rid of the EGR can be beneficial since the hot EGR tube/system is located just above the rear of the intake and is the main cause of the dreaded rear intake oil leak. The excess heat causes the RTV to fail.

The AIR system - I'm pretty shure that if you just leave the AIR fuse in place you'll be ok. Maybe someone will elaborate a little more about this one. I had mine programmed out. No added performance here, just more room.

 

Your info regarding EGR and AIR is incorrect for OBD-II. The PCM looks for EGR flow into the manifold using the MAP sensor. If it can't see the required change in MAP, it sets a code. Same test as in OBD-I, but the OBD-II test seems to be much more sensitive. Needs to have the codes programmed out, or use a spoof circuit to simulate the MAP sensor reaction and a resistor in the EGR vacuum solenoid circuit.

AIR will not set a code in OBD-I as long as the fuse is good, but in OBD-II the PCM cycles the AIR pump and checks the pre-cat O2 sensors for a sudden increase in O2. Again, you will get a code, and it will need to be programmed out.

The codes need to be programmed out correctly, or you will get "system not ready" flags, and two "not readies" may fail you depending on your local inspection laws.

I put together an engine that could make 500HP on motor, and pass NJ rolling emissions, with all the "smog" systems intact. (They obviously didn't do a visual, or test it with the 300-shot ). AIR and EGR have no affect at all on performance, because they are not used at WOT. EVAP may be used at WOT, but you haven't mentioned removing that.... but it is part of the "smog" system.

 

Ok - thanks

 

Injuneer,

Could you expand on what you mean by "programmed out correctly? I had my codes for AIR, EGR, and Rear O2's programmed out when I installed my headers, however when scanned I get the "Not Ready" indication, however my SES light is never on for these reasons... perhaps my codes were programmed out incorrectly.

 

I would like to know about the "programming out" the codes as well. I would like to eliminate the smog stuff as well. I do not have any emission inspections where I live.

 

ok thanks guys, i am changing my opti and was thinking of pulling all that **** off while i was there.

but i will just wait till i pull the motor and rebuild it to change everything else, then i only have to have it reprogramed once and be done with it

 

You have to ask one of the "tuners" how to avoid the "not ready" flags. I stopped using my stock PCM 7 years ago.