ok, i'm trying to figure out the sound my engine is making. at first i thought it was a ping. now i'm not sure. how does someone distinguish the difference b/w pinging and a exhaust leak? i heard the injectors can cause noise but i wouldn't think i would be able to hear them over the exhaust while accelerating? the engine noise tends to be louder at lower rpm's but that might be because the exhaust sound is louder at higher rpm's thus masking the engine noise.