A couple of months ago my CEL came on. When I checked the code, it was 0505. Then a couple of weeks later it came back on. Got the same 0505 code. It stayed off for about a month and a half..and then it came bak on . My knock sensor code came on and its been on ever since. I had reset the ecu and it turned off and it stayed off for about a week. its been on for a bout a week and a half now. and all of a sudden it jus turned off. I REALLY FEEL a DIFFERENCE. The car hade a pretty weird idle earlier today, and then when the CEL turned off, it went away, and my car actually pulls hard. I was just wondering if you gys can give me a little input.

 

the knock sensor harness is probably bad. i would suggest replacing it. i say this because of the inconsistency of you getting the code. while ur at it u might as well replace the KS if ur miles are any where near 80k or more