cec1984

I have a 2002 Acura 3.5RL with 171,000 miles on it. It runs great, but when the weather drops below 30 degrees F, the CEL comes and code P0325 is stored in the ECU. This never happens in warm weather. I am running 89 octane (plus) in the car consistently, and the spark plugs do have about 100K on them. Before I have the knock sensors replaced (big job), I am curious if anyone has had any experience with this. I am tempted to switch to Premium fuel first, and replace the spark plugs second. If I do, what plugs would you recommend, platinum or iridium? Any help would be greatly appreciated.

Thanks,
Carl

2000RL

The Acura owner's manual specifically states you should use a premium fuel blend of at least 91 octane or higher . The ECU and knock sensor will adapt to the running a lower octane gas but you can see it eventually will lead to other issues such as the one you have encountered especially now that refineries are switching to their winter blend gas. I myself regularly use 93 octane gas which is pricey however, I do believe it will avoid knock sensor problems along with any number of O2 sensors going bad prematurely which are also pricey to replace. Acura recommends replacing the the spark plugs at 105K miles or 84 months so you are well past the time window for replacement. I would suggest replacing your spark plugs (either platinum or iridium will work fine) unless you know they have been changed already and switch to at least a 91 octane fuel blend and see if the situation gets resolved. You can also troubleshoot the knock senor itself prior to having it replaced, see link below. Good luck!

http://www.troublecodes.net/pcodes/p0325/

omfghi2u2

What does replacing a spark plug do? I am at 245k and I dont remember the last time they were changed..

2000RL

Replacing the spark plugs is recommended if you are having trouble starting your engine, it's idling rough, misfires, lacks acceleration or has excessive fuel consumption. Or if you get a trouble code like P0303 for cylinder misfire.