ya depend on budget too.. as told by steve here better u go step by step then u can understand the gain and losses you get from mods..

I think you still dont understand... perhaps you was looking for sound effect not performance.

We cant judge your car condition from the forum futhermore if your car is auto, openpod will make it worst. Let me recommend you your first step.

1> Threebond your throttle body.
2> Change your oil and protect your engine with Lambda premier.
3> Now check your car vacuum and compression.

if everything ok, save the money just go and reflash a custom rom with wideband test.
If manual car then you may use open pod. If auto just use the drop in.