2010 Sierra 5.3 - check engine light - throttle lag (Update 1/18/24)

Does it struggle at idle or in turns at low power?

Does the issue get better or go away if you fill up with gas?

Also possible the pins in the wiring leading to the sensor are corroded or burned, look at them closely if you haven’t.

Not much help to the specific problem but I'd say take it to a trusted mechanic. If its actually a simple problem, it won't take much labor to fix it.

If you keep going to Autozone route, be sure and save the OEM parts you take off in case they are good. The repair bill could really escalate if eventually a mechanic has to buy OEM parts to replace the parts store parts AND also fix the original problem in the first place. There is a decent chance the chinese knock sensor was bad right from the box too.

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How many miles?

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Just over 100k.

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Have you changed plugs and wires?

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I haven't so I guess that's long overdue. Damn thing has been running great though.

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If you keep going to Autozone route, be sure and save the OEM parts you take off in case they are good.

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Yeah I save everything.

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The repair bill could really escalate if eventually a mechanic has to buy OEM parts to replace the parts store parts AND also fix the original problem in the first place.

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At this point I'm only in for $25 plus about 30 minutes of cursing. I usually like to try a few such cheap fixes before taking it in. I understand that this might be beyond my skills/knowledge though.

Did the engine light ever come on?

I hear ya though, that's a cheap thing that I can do myself and needs to be done regardless.

Check the plugs when you pull them. If they're bright white and clean, you probably have an upper intake gasket leak. Common thing on those Chevy V8's from 99 to mid 2000's. Not sure about the newer V8's.

If you swapped the knock sensor and you're still having issues, check the wires going to it for any cuts or ground issues. You could also have an issue with the PCM/ECU. Which I may take to a mechanic, just because the money you pay at that point will probably be worth the headache you'd have on your hands doing the repair and ECU programming. None of it is hard, but it can be frustrating and time consuming. Especially since most mechanics will have seen this exact problem 100 times over. Also, if it's something else they'll hunt it down for you.

In the interim, you may want to try a few tanks of premium gas, or put some octane boost in your current tak if it's fairly full. Sometimes a batch of crappy gas can cause some LSPI and set off the knock sensors and cause it to pull timing, which is where the laginess and power dips come from.

Spray some ether on the throttle and give it an Italian tune up.

That will fix most 5.3 engine problems.

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i changed both knock sensors, then i changed the whole knock sensor wiring harness, turned out it was a bad spark plug doing it the whole time.

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I'll be damned. Thing was doing its job and we all jump to the conclusion that it's broken.

Yours threw P0333 too?

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anything not working correctly can cause a slight engine knock, even a spark plug not firing making a dead cylinder.

replace the spark plugs and wires before you try to fix anything else, that would habve saved me a shite ton of money trying to solve the knock sensor tripping

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Already on order.

My 2002 Chevy 5.3 has 365k miles. Check engine light has been on for at least last 15 years. Buddy hooked up to it a couple years ago and said lots of codes. I think 6 of 8 cylinders had misfires. To me mine runs like you describe. Which doesn’t bother me. I’m getting hard of hearing and radio drowns out most engine noises. I think my truck is like me just getting old and slow at different speeds. I plan on getting another few years out of my truck and figure the check engine light will burn out at some point. I did have lifter tapping start at 200k but I swapped to Shell Rotella HD diesel oil and that quieted them down. I’m just glad it’s not a 21 year old EV. I would be pissed if I had to stop driving my truck because the batteries died and cost too much to replace but I hear some people saying batteries last forever. Good luck with your truck. Hope you get it lined out.