knock sensors=real bad mileage????

[nuQ]

just a quick question (or two!!!). could a bad knock sensor set your mileage off THAT much????? have the classic symptoms, burping, farting, stumbling above 40mph (although not very severe), and at a steady speed. i never let my gas go very far below 1/2 full, but my mileage seems to stay around 12-15 mpg (and yes, i do drive pretty aggressively!!). as low as 9 and high as 17. any thoughts?? a second question. i'm planning on taking my Q to the local infinity dealer for the all-important consult. the only catch, since my work schedule doesn't permit an in-person appearance, my very cool mother has volunteered to take the Q for me (yes, i've given her the whole list of do's and don'ts---warm up first, treat her like she's made of gold, etc, etc!!!LOL). my question is,,,is the consult at the dealer a no-brainer or should she specify any specific during her visit (bennit infinity in allentown pa)??? anything to insist on???? specific printouts???? thanks! jeffps-she's looking to buy a honda crv (for the looks alone!), trying to talk her into a used i30!!!!!:D

[sultan]

with bad knock sensors i get between 15 and 17 mpg depending on driving mix and how hard i drive. strictly highway and cruise control i've gotten a little over 20 mpg. my knock sensors are definately bad (clear the code and it comes back immediately). i would say to check the codes yourself with the little screw on the ECU, but i think there's something else wrong besides the knock sensors (unless you have a very heavy foot).

depending on what the dealer wants to charge for using the consult, doing a power balance test is always good.

[nuQ]

what exactly is a power test balance and what does it test??????? maybe i should have it done too???????

[nuQ]

BTW-quoted $72 for the consult.