i installed a BMP chip in my 92 325i today, i am happy with the perfomance but at full throttle in the lower RPMs in higher gears there is a noticable sparkknock. I can easily drive around it and know that the car shouldnt really be floored in 4th at 35 mph, BUT i still dont like the fact that it does it at all. I filled it up with amoco 93. Dirty Injectors? should i switch back to standard copper plugs? Thanks for the help

Use the BMW recommended plugs, first. Platinum plugs suck in BMW engines. Also, make sure it's not just that particular tank of gas that is bad. When was the last time the fuel filter was replaced? Have you tried BG44K injector cleaner?

It could just be a build-up of carbon on the valves creating a less-than-optimal fuel mix and carbon on the pistons creating hot-spots resulting in preignition.

Why the BMP chip? Why not Jim Conforti?

JamesM

Thanks for the tips, as to your questions, the fuel filter is about a month old (i replaced it when i replaced the fuel pump) And about the chip- i went with BMP because even though i have read several posts talking about the Jim Conforti chips, i couldn't find one anywhere.