Been searching for possible causes of hesitation and found that our cars go into a "secondary" fuel matrix after 4000 rpms. I've noticed that my car hesitates but pics up instantly after 4000 rpms. My question is what does the car go into before 4000 rpms? And what controls this "fuel matrix" at this time?

Originally posted by Hamgumball
"secondary" fuel matrix after 4000 rpms.
what does the car go into before 4000 rpms?

Uh, the PRIMARY matrix?
The oracle says: Search for 02 sensor.

What controls the primary matrix, I'm assuming its not the Map sensor because our cars can run without it until 4000. And I replaced the O2 sensor 2 weeks ago. Better yet, does someone have some links for light reading on the topic?

Originally posted by Hamgumball
links for light reading on the topic?

http://www.heavenz-not-0verflowing.com/files/Tech_Info_Man.pdf Pages 1-37 thru 1-51.

http://www.2gnt.com/www/corbin/mfi.html