just did lts and a summit universal x-pipe. my question is that do you need rear o2 sims if you get the rear o2's programed out of the pcm? from what i hear they are part of the maf sensor circuit, which i'm getting 2 codes for (one is p0100 and i forgotthe other one). it is an obdII, 97 z28.

maf is not ported, or aftermarket, and i aleady got them programed out

 

I don't think you need sims if the rear O2s are programmed out. You will have to keep the wires from shorting or grounding to anything, though.

 

If you get your rear 02s programmed out of your PCM you don't need O2 sims.

As for the PO100 I got the same code about 2 weeks after I did headers. I still haven't fixed it but I think it is in my 02 sensor wiring, the maf sensor and O2 sensors are on the same circuit. Are you blowing the Eng Sensor fuse under the hood. If this fuse is blowing you are going to need a multimeter to find the load side of the fuse. Then will need an ohm meter and then start unplugging connectors in the circuit until you get a reading of 0 and then you have found where your short is.

I hope this helps you some.

 

all my fuses are good.... and i'm assuming then my assumption was wrong and the back o2's are not part of the same circuit as the maf sensor...

then that takes me to a new question and i'd rather not start another thread for it so i'll just ask it here

where else could there be a vacuum leak at(besides the tb gasket)? my maf sensor is good, i blocked off the metal egr tube in the back of the intake w/ a vaccum, capped off the two tubes and each side of the engine, and capped off the line coming off the egr solenoid.

 

If you are throwing code PO100 Mass Air Flow (MAF) insufficient signal activity(from shbox.com) you have a electrical problem. The last time I looked The maf sensor and all 4 O2 sensors are on the same circuit.

Do this quick test, take off your maf sensor connector. With the key on engine off you should get 12 volts from the pink to black wire and 5 volts from the black to the othger wire(I think it's yellow) and tell us what you get for voltage.