Exhaust and header question.. for the gear heads

[opekone_1988]

Ok, this is one of those dumb questions that we think we might know the answer to but just need confirmation. Does anyone know if it would make a substantial difference to get headers without exhaust or would it be better with both on.. reason I ask is because I know that back pressure is needed, specially on a 2.5L. Thanks in advance.

[LeGeND42o]

Headers alone would increase power, but the combination of headers and exhaust would preform more efficiently and sound alot better.