97 E420 ticking sound on hard acceleration

[apb]

No ticking at idle (so it does not seem to be the oil tubes). It almost sounds as if it was pinging from low octane as on old cars, but I put 93 octane in it and I think newer cars compensate for that by changing the timing. Any idea what could cause this? Is there some type of sensor?

[Arthur Dalton]

Get the codes and see if there is a Knock Sensor fault code.

[apb]

would the check engine light not be on? can this code be read by a regular obd2 scanner?