2000 Outback Wagon Knock Sensor PO328

[mwells]

I have a 2000 Outback Wagon that has a PO328 Code with CEL light on. The car runs fine. I've been getting a PO420 code for some time, but the PO328 just happened Saturday. I had a local "oil change" outlet change the air-filter for me and they failed to install it correctly. They hadn't aligned the tabs at the bottom where the air-filter mounts and it was "sucking air in" on acseleartion. I corrected this and that's when I got the PO328 code. Is this a knock sensor code..? I plan on changing the front O2 sensor this week along with the fuel filter and PCV valve.

[porcupine73]

P0420 is catalyst system efficiency below threshold. Check for any kind of exhaust leaks. Says to check front faces of the rear and front cats for damage and replace if any is noted; otherwise says contact SOA. Doesn't say anything about replacing rear O2 sensor, but others with experience may have solved it with that?

 

Not sure about P0328; all data doesn't show any info for '00OBW for this code.

[OB99W]

[...]I had a local "oil change" outlet change the air-filter for me and they failed to install it correctly. They hadn't aligned the tabs at the bottom where the air-filter mounts and it was "sucking air in" on acseleartion. I corrected this and that's when I got the PO328 code. Is this a knock sensor code..?

Info I have says: "P0328 Knock sensor circuit high input"

 

Any possibility that you accidentally disconnected the knock sensor while working on the air box? The links below may not exactly depict the situation on a '00 OB, but they should give you an idea on what to check.

 

http://www.scoobymods.com/forums/attachment.php?attachmentid=3057

 

http://www.scoobymods.com/forums/attachment.php?attachmentid=3060

[nipper]

how many miles are on this car?

[mwells]

The car has 98K on it. Where is the knock sensor connector located? Is it near the air box? I'm not a mechanic, so excuse my egnorance. Also, I will be changing the fuel filter, the service manual says to disconnect the connector to the fuel pump...then start the engine til it dies...and then disconnect the lines from the old fuel filter. Where is the connector for the fuel pump located?

 

With this knock sensor code(PO328) is it dangerous to drive the car?

 

Thanks for all the help.

[porcupine73]

I don't think driving with that knock sensor code is dangerous because I'm guessing the ECU retards timing probably to its maximum when the knock sensor is out of commission. I'd suspect maybe less power and fuel mileage possibly until it's corrected.

 

For the fuel filter, I usually just loosen the gas cap to release tank static pressure and wrap a few cloths around one of the fuel hoses to the filter before pulling the hose. Some gasoline will squirt out but with the cloths there it doesn't seem to be too bad. The correct way though is as you mentioned to disconnect a fuel pump connector somewhere along the line and run until engine dies.

 

I find the hoses on the fuel filters to be a little stubborn sometimes, so I twist them clockwise and counter clockwise until they can rotate on the filter's barbs, then pull them off. After you put the new filter in and have the hoses hooked up, I like to turn the key between acc and run about 7 times until I can hear the fuel pump loading down a little. This will refill the filter and repressurize the system so you don't have to crank the starter for like 10 seconds or whatever to get it to start again.