Hi to all,

This is my first post so forgive me if my requests have been answered before; I have had a look but haven’t seen anything relating to my question.

I recently bought a used 2004 WRX STI JDM from a reputable vendor; since then I have been realy enjoying the performance as my previous car was a WRX 03. I recently had cause to look at my chassis no. and engine No. and realized that the Chassis, Transmission all have the characteristic numbers and letters they should have. My big question is the engine has obviously been changed as the engine No. does not match the plate that is riveted close to the left shock absorber on the right. The STI Engine NO. is usually marked as EJ20 with a space followed by 7 then two more letters then a 6 which is followed by two more letters; this is not the case with the engine in my car which starts with EJ20-C followed by six numbers.

Can anyone give me an explanation to this unusual engine No?

Just in case you are interested, I have drag raced an Evo 7 and led by 2 ½ car lengths in a ¼ mile, also was faster than an Evo 10 in the ¼ mile by about ½ a car length; yes the car is definitely performing as I would expect, however the engine No. does bother me.

Best regards
farmeronthehill