finding false knock

[sloppymax]

Anyone have any other ideas on where this knock is coming from? I'm still getting 3+ degrees with 93 octane plus lucas octane booster. I went through the catback and made sure everything was tight and there was good clearance. Not sure if it could be the jlt oil separator or something with the cai rattling.

I see you were going to change stations, did that happen? On the exhaust, I would check the clamp on the driver side right under the driver. It would not have been loosened by a catback install but it could be loose. 13mm and it can be tightened on the ground if you are not slammed. I would also look at the main clamp where the catback ties to the stock system. There is one clip on each side of the clamp itself that attaches to a small round post. Make sure the clip is under the post when everything is tight. I doubt the air separator is doing anything to cause, if anything it is reducing knock by reducing oil mist and vapors from going back in. If it is still present after addressing that when I would swap back to the stock intake and see if it still resides.

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[4to8]

Yes I changed stations. U havelossfrom multiple stations and some with octane booster, all show about 3 degrees of retard in the upper rpm range. Until then it's adding timing so I'm pretty sure it's false knock I need to track down. I never thought about that one clamp I was just redoing everything from the cat back install. With the oil separator I was thinking it may be close to the head and might tap under load but that was not the case. I changed it out and the knock was still there.

 

[sloppymax]

Another thought depending on your tune device would be to do a KAM reset. Not sure how that works on any other devices besides the SCT. If it is not available then pull the negative terminal overnight. Drive around again and see if the knock is still there after you check the exhaust for the earlier items.

 

[dubster99]

Have you checked to see if the exhaust is hitting anything?

 

[4to8]

Yes I check all the clearance from the catback. The only thing close is the tips in the cut out. They doll have a 1/4 to 1/2 inch clearance.

 

[Reds197]

Get the booster out. Get 100 unleaded race gas. It is a 100% fool proof way to know. Some octane boosters make it worse.

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