Hiccups? Knocks at same RPMs?

[Garrett M]

Hmm ive noticed latley my 95 M3 will slightly hesitate or knock when im driving it...I can only remember the RPMs around 3500 in second gear, but it has happened at different RPMs in different gears. Any help

[LuxoM3]

let's look over the easy stuff first...

1. Fuel filter - been changed on the last 2 years?
2. O2 sensor - been replaced over the last 5 years?
3. Air filter 0 been changed in the last year?

I personally think #2 as the car relies heavily on the O2 sensor for air/fuel mix.