This is my first post to this forum and I apologize if it is misplaced. I have looked everywhere on the forums and cannot find what is causing my Check Engine Light. about 4 months ago I got a P1421 code from the car's computer. It was still cold here in the north and I figured I would wait...
This may be useful for those running headers, tunes, SC kits, or a combination of mods.
BMW Part Number:
Installation should be pretty self explanatory.
Here's what it looks like installed.
I've noticed an increase in bottom end torque and better gas mileage. Same net...