nice write by soulfly...gave me a good insight into mods. i m have just changed my air intake to apexi power intake and looking forward for more modifications.

i got some questions tho before i move forward :-

1) will replacing air filters and/or extractors affect the air fuel (AF) ratio of the car since AF ratio is oredi tuned for stock engine?

2) does this affect fuel injection engines? (i understand fuel injections have sensors to detect air volume from intakes & auto adjusts to condition)

3) after modifications such as changing air filter types or replacing extractors, is there a neccesity to retune the engine??

4) when is retuning of engine required / and in what conditions?

5) what are estimated costs for tuning an engine??

hope any guys can help answer my queries.

blueray