Performance Chip for a 92 400E? Yes or No
 

Thinking of putting one of these preformace chips (jet or something smilar) in my 1992 400E? Anyone have any exprince with these type preformance chips? negative or positve info? Do they do what they claim? Will they affect smog checks?
Thanks

I put a powerchip in my 300CE, it affected smog, illegal in CA. The performance gain is all up top, feels a bunch slower on takeoff and such, but I also got better gas mileage, mostly for supercharging, if its all you're going to do to your car, dont do it. Course, it might be different on a V8. OH, unless sound is a real big deal to you, it is for me, makes the car sound super cool. Louder, but not too much, and not tacky broken muffler, Mower sound.