Well after the car sat for 10 months I fired it up and there was 1/2 tank of old gas in it. I went to gas station and filled it up. When I got to emmisions station I failed with 598 at idle and I have to be under 200. Now heres what has been done to the car since I got the car. New 24lb injectors, cats ended up being gutted, I put a 160 stat in and a "175 on 165 off" fan switch. Do you think he old gas is some and the temp is other? I pass with no cats in my other cars no problem. The temp is putting and keeping the car in closed loop.

 

Also I was thinking of disconnecting switch so computer will tell fan to come on at 223 degs and then rehook up after going through. Do you think that will dropp hydrocarbons down enough?

 

You NEED to let that engine heat up right beofre you go to the sniffer. Put the fan setup back to factory specs and drive the around all day and run a bottle of "emmsisons in a can" from Autozone.I used it and my car passed MASS inspction with no cats, AIR pump or anything. Try it and see what happens. The botle will tell you to put it in to a full tank and run the tank empty then go get it sniffed. I put the bottle in to a empty tank and added 3 gallons of fuel and took it straight to the inspector. it stunk but passed

 

BOTTLEDZr28

Just wanted to tell you that your car is BEAUTIFUL. I have a 91 Z28 also. I'm always looking at the 91 Z28's and have seen some really nice cars out there but, your car is REALLY nice. I love that silver. You've done a really nice job. My car is 100% stock with the exception of some flowmaster mufflers. She needs a paint job but, other then that she purrs. I see all the mods you have done and WOW!!!
We have two camaros that we're working on. A 70 camaro that the engine is already done and my car ( the 91 ). We are going to finish the 70 and then start on my car so hopefully my car will be looking as good as yours soon.
Take care