Hello all. I have a quick question for people getting their car inspected with a special tune. First off I Have a 2008 roush 427r. IT comes with 4.6 liter m90 supercharger from roush. I have a host of suspension mods; I'll post some pics later. My question is that I had kooks custom long tube headers with matching x-pipe with high flow cats installed. At the same time a 93 octane tune from lethal performance was installed via an sct tuner. These are the only mods to motor. To pass inspection in mass they have to plug into your obd port to see if their are any codes. In the directions with the sct tuner they say to return car back to factory tune before bringing to dealer so as not to lock out your sct tuner. Sct is unsure whether this will alter my tuner as it is not an update from ford and they are not familiar with mass inspection. Lethal performance said the same thing. The car runs great and has no check engine light on. The car will not run right(detonation=blown motor) without a custom tune due to the headers and I'm not about to have them removed just to pass inspection every year. I figure I'm not the only one who has come across this issue. So any one have answers suggestions?

 

The problem will be in whether your rear O2's were turned off in the tune. If they are off, you will not pass inspection. When they plug in to your OBDII port they are checking the emissions monitors. If the rear O2's are off, some monitors will not show as "ready".

So first, you have to make sure the rear O2's are turned on in the tune.

Second, you cannot return to the "stock" tune. Do not even consider doing this. Even without the headers, your engine is not stock - it has an M90 on it. For example, you no longer have the stock CMCV's in the intake. The CMCV motor must be turned off in the tune or you will throw codes. If you are throwing any codes at all, you won't pass inspection.

Third, if the rear O2's are turned on and you are not throwing codes because of the hi-flo cats, you are lucky. Depending on your combo, some shops can tune so that you don't get codes (Pete at Performance Dyno in Loudon, NH is one that is kind of local). However, with my combo, tuning to get rid of the codes wouldn't work, so I had to get Kooks "Green" cats and they have worked flawlessly. I pass RI inspection with flying colors.
Mass has gotten real picky on inspections lately, so even if you don't have codes, they may still give you trouble.

 

Your concern is whether the etest will change the tune? A simple etest wont, it simply reads info from the obd. It wont alter your tune at all. Whether you pass or not is a different story. Id give it a shot though. In canada here, it scans for "not ready" codes. My rear 02s are off, so it doesnt show as not ready.