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I need some input on a spark knock issue under light acceleration for my 2003 4.8, manual trans silverado. Went to 89 octane. Changed PCV, plugs, clean air filter. Will a bad knock sensor cause it with no CEL? Been chasing this for years. Is the winter gas causing this. I forgot what it is but the octane rating changes because of temp change. i think. Thanks and please give me some kind of help.
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5.3 manual; getting random hesitations under any throttle input/gear/speed. various durations & intensities but frequent.
i've ran a tank of HEET + storage stabilizer (just had some left), then a tank of 93 with seafoam. i've replaced the fuel filter & pulled/cleaned the injectors.
no CEL or codes (other than a persistent P0446 whenever i'm below 1/2 tank).
even updated-er update: unplugged the knock sensors & drove around. does the same thing.
spark plugs & wires look good (plugs have 20k on them since new with cam spring last year).
is this pointing to coils?
could i zip-tie on the coils from my LS1 (square style vs the round LM7 ones) to see?
they have the same main harness connector