You are right, throwing parts at the car is not the answer. That's why I'm asking those wiser than me before I jump in. The wide band a/f ratio meter is good advice. If we assume for a moment that the 93 and later 400E did suffer the same fate as the 93 and later 500E did, (which I strongly suspect it did) we can also assume (bad choice of words I know) that my 93 400E would make more power if I added more fuel at WOT. What is the BEST way to do that? Short of trying to find a 92 brain, Wouldn't finding a chip programed like a 92 help? I know there are a lot of bunk/bogus chips out there, But surely there is at least ONE brand that works right...right? What year was that 500E? What where the horsepower and torque gains? Thanks again for your help Jonathan. If you ever get tired of your 87 Hammer, let me Know. I have the Car and Driver article that featured that car. Do you want a copy? You probably already have it but I thought I would ask. Regards, Eric