WainiacS

It's the strangest ping metal on metal ping sound that runs in sync w/ accelerator.
Sounds like it's coming from around #4 cylinder area under rear manifold.

Car seems to run fine idles@ 750ish CEL has flashed intermediately and I caught the codes.

First time:
P0100 Mass or Volume Air Flow Circuit Malfunction
P0110 Intake Air Temperature Circuit Malfunction
P0304 ignition coil

Cleaned MAF; Cleared codes and drove around and got p0305.
Cleared and haven't gotten a code.

But I don't believe that the ignition coils have anything to do with this sound.

Any guesses... Thanks

Lexmex

Does the ping show up all the time or sometimes more than others?

WainiacS

UPDATE:

So I took it in to my local guys (Not Toyota)... And they said the #4 spark plug wasn't seated properly. The metal ping was actually vapor being expelled rapidly...

I changed the entire set of coils and plugs maybe 2 years ago - must have finally vibrated lose. There was alot of corrosion build up around the plug and orifice that had to be cleaned. Other than that a new plug and ignition coil and it sounds good as ever.

Thank you for your time.