hocbj23
+1y
Because the Maz fuel management system in stock form is a closed loop system which means fuel,fumes from the tank, both fresh and recycled air and some exhaust gasses all feed into the carb AND exhaust to ensure an acceptable level of unburned hydocarbons,(pollution).When u remove the reed valves and other pollution equipment,there are still sensors like an 02 sensor,etc that detect faulty readings and start telling the stock carb(?) to continually adjust mixture based on the faulty reading.Therefore idle problems,stumbling problems on acceleration,even worse fuel mileage and typically a very rich mixture leading to clogged cats and fouled plugs often result.If u think that u can just disable all the sensors,think again as when u do,everything defaults to a "limp home" mode and the truck will barely run.That do it for ya?A Weber carb or a Holley 5400 and slightly modified exhaust is an open system (air in the top,exhaust out the ass) that can be manually adjusted to richen or lean out the mixture so the truck can pass emissions.Even with a modified engine I sill run an 02 sensor and recycle tank fumes and my truck gets 4mpg better mileage than the stock system and engine and passes Tennessee emissions testing.It also runs a sub-10 second 1/8th mile.Class dismissed.BJ