HELP just got a 99 Q45

[LNSears]

Hi,
I just got a 99 Q45 its awesome but it has some minor issues... or so I think..

It runs great for a 99. However it does have a slight knock during idle. I did the BG fuel system cleaner as well as the fuel injector cleaner on it and am getting better gas miles.
I just got P codes
0325 - Knock Sensor
0135 Front 02 sensor
1320 - Ignition Signal
0161 - Rear O2s Heater
0160 - Rear 02s Bank 2

Thats pretty much all I know. I don't know cars at all but I do know I really want to take care of this car it belonged to a mechanic who took very good care of it. When I got it he also gave me 8 new fuel injectors for it which I need to have put on.

Questions: are all knock sensors the same? can I just buy 3 or do they need to all be different?

Igniniton Signal... I have NO clue what that means at all

I'm slighly familiar with knock sensors because I was looking into what was knocking...

if someone could help me I would really apprectiate it!

[marcyprojects]

knock sensor and ignition codes probably related. if you have a bad knock sensor it will retard the engine timing. replace the knock and both of those should clear. as for the O2 sensors, same thing. If one is bad you can get codes for 1 or all of them. Start with the main o2 which is the one closest to the engine. I think our cars may have 2 main o2 sensors, not sure. pull and check condition, may just be dirty. Sometimes you can soak them in seafoam or gas to break up the carbon.

[maxnix]

Just two KS, but they are at the bottom of the top deck. Check in with ParanoidJack's excellent article on how to get the job done. You will be amazed once it is back together and everything is clean. Take lots of pictures as you take it apart and replace every wear item.