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Roger
Roger, BMW Master Tech
Category: BMW
Satisfied Customers: 3037
Experience:  10 yrs. experience as BMW Master Technician, shop foreman and dealer.
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My 2005 745LI hesitates going uphill at around 45 miles per

Customer Question

My 2005 745LI hesitates going uphill at around 45 miles per hour it jerks and sounds like it has a "pre-ignition" problem. If I hit the accelerator harder, it will straighten up a little but not smoothly.
JA: Are you fixing your 745li yourself? What have you tried so far? Anything else you want the mechanic to know before I connect you?
Customer: I brought it to a certified BMW mechanic who tried cleaning injectors and testing each plug. They were unsuccessful.
Submitted: 21 days ago.
Category: BMW
Expert:  david craig replied 21 days ago.

Hi Im David, when it starts jerking does the check engine light start blinking?

Customer: replied 21 days ago.
I've had the "check engine light reset several times. It comes back on indicating a secondary system problem. I can't remember what the code is
Expert:  david craig replied 21 days ago.

having the code would help tremendously. other than that i would say to have a back pressure test done to check for clogged cats.