Possible power loss or all in my head?

[8thLS6]

A while back I got a service engine soon light w/ a code for cat warm up, so says the shop that cleared it for me. I've gotten the light again a few times, but due to work have never been able to get it checked before it clears itself!?! So anyway I've ran a couple additives in the gas such as mmo and recently stp fuel cleaner, and a small amount of mmo right before oil changes. Never had a problem before. As of recent, it seems as if its smoothen the cars power out, but the car feels kinda boring under normal driving. But still feels like itself if not more of a beast under wot lol. I plan to get new plugs soon, since the current ones are ngk v gaps. Didn't know at the time I should've gotten platinums. And also get my trans fluid change because the shifts feel kinda funny too. No slipping, but sometimes it seems like it wants to ride gears a little longer.

So long story short if it was anything important like a clogged cat or bad o2 sensor, wouldn't the light remain? Last time I've gotten it was probably back in January.

Thanks for any input

[wetamup2k3g]

If it was severe, the light would stay on. From what I understand, if the condition does not repeat itself in five starts, the CEL will go out. If your cat was really bad the condition would repeat often enough that the light would stay on. It's probably on its way out but it should pose no drivability issues if its only a P0420 or P0421 code. A clogged cat however would probably cause the same codes I think and would probably kill some performance. Your trans fluid and spark plugs needing change out is probably what you feel is affecting your performance. Hope this helps!


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[8thLS6]

If it was severe, the light would stay on. From what I understand, if the condition does not repeat itself in five starts, the CEL will go out. If your cat was really bad the condition would repeat often enough that the light would stay on. It's probably on its way out but it should pose no drivability issues if its only a P0420 or P0421 code. A clogged cat however would probably cause the same codes I think and would probably kill some performance. Your trans fluid and spark plugs needing change out is probably what you feel is affecting your performance. Hope this helps!


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Thanks for the advice. I was getting the code mainly everytime I filled up, but I've had more than a couple fill-ups since the last light appearance and it hasn't appeared since. I'm just gonna focus on plugs and trans fluid, since the car isn't smoking, making any abnormal exhaust sounds or odors.
Thanks again