Air intake muffler delete on a Pontiac Sunfire

[Frank Lee]

I doubt GM- or anyone- released new vehicles with built-in hesitation and sputtering. So there is a problem with this vehicle that isn't systemic across all vehicles yet the implication here is that all or some or many vehicles will benefit from a mod that seems to address the problem.

Modding a vehicle with a defect without first getting it to good stock tune is kinda... well... bad form.

[Frank Lee]

Originally Posted by moorecomp

Autospeed has a great 5 part article on this. It shows that reducing the differential between atmospheric and intake (not manifold) pressure does have an effect on performance at less than WOT.

Eliminating Negative Boost

It does? Since reading it through was too much like Chinese water torture, I looked at installments 1 and 5. To summarize, at the very end he claims elimination of negative pressure, but also admits to changing several variables AND in the final analysis the vehicle did not produce any more power or fe. Right?

[Porxster]

It breathes in a little better,but a cold air intake would help furthermore.Still a good cheap mod coupled with an high flow air filter.
Thanks for you're post.