I just bought an 01 cont and am having an issue with a beeping noise...rather obnoxious...everytime I start my car for about 15 seconds (seems longer) and sometimes while driving (usually after about a half hour for 15 seconds) It is a slow beep unlike the seatbelt warning. I was wondering if this is a simple issue to fix or if I need to pay for diagnostics. Thanks.

The airbag module will beep if the warning light isn't working. Does the airbag dummy light turn on for a few seconds when you first start the car?

I iwill check thanks for your reply.

I was told by a friend it doesn't really matter if I use 91 on my 01 cont v8 4.6. Anyone heard the same or know if it truly does. Thanks.

The DOHC 4.6 is made to run on 91 octane or greater. Lower octane gas will cause the engine to knock. It has knock sensors, but the engine has to start knocking (which isn't good for it) before the computer can react. It does so by cutting back the ignition timing and/or richening the fuel mixture. That gets rid of the knock, but it also slightly reduces power & fuel economy.

So the short answer is: Yes you can save 2 or 3 bucks per tank by running the cheap stuff, but it's slightly bad for the engine and the reduced fuel economy means you probably won't actually be saving any money.

http://www.lincolnvscadillac.com/showpost.php?p=255475&postcount=5

segxr7 "The DOHC 4.6 is made to run on 91 octane or greater. Lower octane gas will cause the engine to knock. It has knock sensors, but the engine has to start knocking (which isn't good for it) before the computer can react. It does so by cutting back the ignition timing and/or richening the fuel mixture. That gets rid of the knock, but it also slightly reduces power & fuel economy.

So the short answer is: Yes you can save 2 or 3 bucks per tank by running the cheap stuff, but it's slightly bad for the engine and the reduced fuel economy means you probably won't actually be saving any money."

I don't think you got that right.

"Newer cars have anti-knock sensors that will retard timing long before you hear engine knock." ~ 20 year Ford Tech

I never ran 91 in 93 Mark VIII and it ran great and was still faster than my wifes 94 Mark in witch she always ran 91. the 93 was just faster