hey all, new here and just picked up a clean bone stock 92 RS. this thing is oddly stock. it failed emissions here in az, even after new plugs wires cap rotor oxy sensor etc. no codes i am thinking its just the catalytic converter. probably do that when i throw on an exhaust. where i need help is with the rear. the guy i bought it from said it had a rear swap around 100k. supposedly the rear was swapped with a 96 camaro for the rear disc. its apparent that this is true since it does have rear disc and the gear ratio is lower cuz at 80 on spedo im actually goin 65 approx. paced with my wifes new car. where the prob is at low speeds i here a slight grind or drag. what i have been told is this would happen using the stock master cylinder. supposedly a master cylinder designed for drum rear keeps a certain amount of pressure on the rear for the drums. this small amount of pressure i am told would keep the rear new discs to drag. supposedly the difference is abs braking. hoping to hear from someone that may know about this. wondering if a simple fix would be to swap the master for one for a 96..... thoughts. thanks for any help

 

I believe you need a proportioning valve for that set up since it was drums to begin with. BTW, I am in AZ as well, what did you fail on? CO2, or HC?

 

i failed hc and co. ran it thru today after the original results were hc 3.57, co 14.59. today it came back hc 2.68, and co 12.43. the standard is hc 1.0 and co 12.00. so im not too far off, and it improved with the new cap rotor, plugs, wires and oxy sensor. gonna check timing and probably replace the cat when i decide on a exhaust set up

 

Was that loaded, or idle? All of the items you changed will help, but you will still need to polish the fuel, our az fuel sucks, it seems necessary to add alcohol to just about anything especially in the tucson area. I doubt your timing is off too much, but it wouldn't hurt to check.

 

if it is indeed a 4th gen rear, it would need 4th gen wheels or the stock wheels would stick out a good 2 inches on each side. 3rd gens did come with disc brake rears. now what you said was correct, there is a valve that keeps a small amount of pressure at the rear for drums. the noise youre hearing the pads dragging and theyre probably worn past replacement. you will need to replace the proportioning valve with one meant for 4 wheel disc, but the master cylinder can stay

 

Thanks microkid. And yes my rears do stick out about two inches. I can tell the wheels were for a standard 89 rear. I need to find some American racing torq thrusts that have the correct back spacing. It doesn't bother me much but I would like to tuck the wheel back in the well. Thanks you just solidly convinced me that what I was told is correct. Btw the proportion valve for a 96 appears to have some sort of CPU or electric controls, is there any more info you can give me or point me in the right direction to remedy my problem? My 92 valve appears to be just mechanical

 

does anybody have a suggestion on what proportion valve i should get to remedy my problem. my rear does stick out and i do have a swapped rear so i am pretty sure its from a 96. my last post i was under the influence i needed the abs controll, i have learned that i just need the valve..... suggestions? and i checked the pads in rear are not dug into the rots, so new pads and the valve i should be fine. also i got the codes 32 and 54 AFTER i left emissions, so i am going to replace the egr, it looks old and vac lines are good, hopefully its not the solenoid, the egr moves but rough.... hope its not the solenoid. and i am going to replace the fuel relay as the oil pressure switch works fine. hopefully that relay change and filter change should remedy the 54 code. i am new to camaro but not wrenching. thanks for any help you guys can give.

 

For sure you need to address any codes, but I don't believe your EGR will have that large of an affect on either CO2, or HC numbers. I wouldn't run it through emissions until you have cleared all codes, and was able to look at the cat.

 

the egr valve solenoid is available aftermarket for around $50.code 32 is for the egr the code 54 is low fuel pump voltage

 

just get the proportioning valve for the year of your car. the rear has no effect accept for the fact that its disc brake equipped. calipers are slightly different, but only marginally. you could also take the time to get an adjustable prop valve so you can adjust bias, if you wanted.

also, what engine is in the car?