So can someone explain to me what it means when you read that an engine is an even fire or an odd fire? Also what is the 5S-FE enigne?

Isnt that usually associated with V-engines...V6`s etc

http://en.wikipedia.org/wiki/V6_engine#Odd_and_even_firing

I think its 1/3 2/4 fire pattern but its been over 3 years since I knew for sure.

The 5s-fe engine is Toyota's S-series engine in the US , i think they use it because its a cheaper engine and it uses older technology. 2200 CC , about 135 HP and 145 Ft-LB of torque ( i dont know the European units), basicly found in the USDM Toyota Celica Gt and Toyota Camry. Hope this helps.

Thanks. I have been looking into more and I think it only applies to V6 engines. Some rare V6's are odd firing, the rest of the engines are even.