This came from a Gadgetman Groove customer in Texas. Remember, where he lives there is NO Smog Check.
He wants to be anonymous. Ron would have LOVED this dude!
Disclaimer:
NOTE: We are NOT telling Anyone to delete Federally mandated Emissions control Equipment!!
This is posted as information, only. This is what ONE guy did to his truck,. He's pretty pleased with the results. But, seriously altering or removing Government mandated Emissions equipment can bring penalties. So, observe what you see here, and ponder that before doing anythng.
For those who must deal with Smog Checks, think hard of what he describes here, then consider what YOU could do.
Here's what he sent me:
Re: Change descriptions 1998 Ford F-150 5.4L engine
Tracy,
Here is what I decided to do, how I did it and how it works.
I figured out a way to trick the EGR vaccum sensing valve and the DPFE sensor into thinking all is working as designed (both are connected to the vehicle's computer). I removed the EGR valve permanently from the intake manifold, installing a blocking plate on the intake manifold where the EGR valve was mounted previously, preventing useless problem causing exhaust gas from entering the intake manifold. I cut both the mounting flange and the threaded boss off of the EGR valve leaving only the diaphragm and piston (see before and after photos attached below). I hung the diaphragm using a zip tie close near where it was originally mounted where the blocking plate is now. The vacuum line from the EGR vacuum switching valve is still hooked up to EGR diaphragm. But the difference is no exhaust manifold gas is being fed to the intake manifold. That leaves the existing DPFE sensor and the EGR Vacuum switching valve in place still hooked up as they were originally from the factory. These two devices operate just as they did previously, sensing the EGR valve is supplying exhaust gas to the intake manifold which it actually isn't. By doing so no codes are thrown in the system. Again, this completely eliminates exhaust gas being fed into the intake manifold. Thus, ridding a noncombustible inert gas from the fuel / air mixture in the engine cylinder, permanently closing off a major vacuum leak, the EGR valve itself! I plugged the hole in the driver's side exhaust manifold, doing away with the tube that previously fed exhaust gas to the EGR valve. Note: Nothing wasted, I built the ERG block off plate and the exhaust manifold plug out of the pieces I cut off of the original EGR valve (photos below).
I eliminated the crankcase tube (has the same function as a PCV valve basically) that ran from the driver's side valve cover to the fresh air inlet just upstream of the throttle body. Since I installed the grooved throttle body and eliminated the PCV and EGR valves the increase in vacuum is causing this crankcase tube on the driver's side valve cover to suck up oil unnecessarily from the engine below. The port that this valve cover tube connected to upstream of the throttle body has now been capped off. I put a 5/8 inch i.d. Uni Filter brand oil breather available from Summit Racing, stock number UFI-UP-104, on this valve cover tube down on the valve cover after shortening the tube. So by earlier eliminating the PCV valve and putting in it's place a oil breather from CJ Pony Parts on the passenger side valve cover and now eliminating this tube running up from the driver's side valve cover to the throttle body by installing a second small breather, neither valve cover now feeds oily vapor to the intake manifold. Previously crankcase oil vapor and exhaust gas were fed into the intake manifold heavily gunking up the intake manifold but not more! In the end now only filtered air will enter the manifold! My goal was to clean up the commonly found oily gummed up mess in throttle body and the intake manifold. This could only be accomplished by eliminating unnecessary supply sources of oily vapor and exhaust gas.
With extensive testing the air flow through the IAC cannot be restricted even the slightest amount without causing erratic uneven idle. I tried but as to the IAC, its all or nothing it proves. So with this being said I cut a 1/8 inch solid neoprene gasket out and blocked the IAC off completely. I painted the factory idle screw on the throttle body with red enamel to indicate the factory setting. I took a Dremel thin cutting wheel and cut a slot in the backside of this 10-32 screw. Taking a thin flat stubby screwdriver normal idle (875 rpm) can be achieved with slightly less than one full turn of the screw. I got lucky, this slight adjustment does not interfere with or intrude into groove function. Half of the idle air supply come over the top of the throttle body butterfly as below.
In review, I have eliminated the manufacturer's intentionally designed vacuum leaks thus creating tremendous vacuum to the intake. Now we drive eight or so tanks of gas and see how our Groover performs. Only time will tell.
I hope this information helps. Bypassing and eliminating factory reverse engineering can be done. No codes are currently showing. I did have one "check engine light" when I was adjusting the idle. I reset it and drove it but it has come on since. It looks like my mods are agreeable with the F-150's computer.
Thanks,
Brooks
Brooks sent along many useful photos. I will try to include them, if I Can!
Brooks, you ROCK!! THANKS!

Tracy G.