Is this engine low compression? I know it might Engine

Do you have any warning lights being displayed on the dash, or OBD2 codes worth posting?

How long have these symptoms being going on?

Did you have a reported OBD2 code that necessitated throwing parts at the problem, and did the replacements make a difference?

Knockoff parts are a thing now, were those parts replaced from a local retailer/dealer, or from online purchases?

Which spark plugs; brand/part# did you use?

What did the old plugs look like?

Did the old coils (COPS) have any carbon tracking?

What did you actually replace?

Did you use Toyota OEM or Denso replacements, or some other aftermarket?

Have you ever used a PEA additive in the gas tank?

Won't take long to clean up the MAF sensor and butterfly valve, then disconnect the 12v for a few minutes to reset the fuel trims. Might help.

 

I'm with SFO where did you buy the plugs & coils? If anyplace other than dealer online you probably have counterfeit plugs and coils. Especially coils.

If she's misfiring she's throwing codes and possibly other codes to tell you wjy its unhappy. What are the codes?

And most importantly has the engine oil ever gotten so low it turned on the check engine light and it was blinking?

 

Yeah dang it, do you mean you replaced the timing chain? I think so, but this "system" expression is confusing.

 

May be time for a compression check the engine may just be whooped. i would have done that before the time chain replacement that's a very big job.

And the aftermarket coils are bad news but I understand as the real coils are $105 each. Ya get what you pay for.

Compression check next.