I found out that my smog pump has been disconnected on my 91 GT. Will it pass emissions since I still have cats or do I need to reconnect it? I live in a county where they just do the idle test and not the full blown dyno emissions testing.
It is very dependant on the individual car and the state or local requirements. Some states or areas may have stricter regulations on the amount of pollutants the car can emit.
Running cats with no smog pump will eventually cause the cats to clog up & fail. High mileage engines burn oil that ends up coating the inside of the cats and clogs them. You may not see any evidence of oil burning, but it is still happening if you have a lot of miles on an engine.
The smog pump provides extra air to react with the exhaust and the catalyst and break down the pollutants into CO2 & water vapor. It shuts off at Wide Open Throttle so it doesn’t use any real power when you want all the power you can get. It just doesn’t make sense to disconnect it on a street driven car.
In Upstate NY the smog pump has to be there and appear to be connected correctly and working. Down state is another story and I don't live there so I don't know exactly what's up.
Yes it does. I got sick of them seizing up and leaving me stranded. Happened to me three times with recondishioned pumps and then one more time with a brand new OEM ($325!) Ford one. It's one less pulley in the loop that may give me problems. The power steering is next...
If you have cats, you might as well hook it back up. I took my smog pump off because I got tired of a "brrrr" sound coming from under my car from where the pipe wasn't connected to the exhaust.