Sorry for the longest delay, I have been at school full time at UTi, now finishing NATT3 (Nissan Advanced Technical Training), then about to graduate, yay! So here is what I have learned so far from car tuning....
1. Upgrading intake, exhaust will cause your engine to pull in and exhaust more air in your engine...remember, your car is nothing more than a vacuum pump working efficiently ;)
2. Engine displacement size (2.0, 2.2) is the amount of air flow that engine can deliver per cylinder, not size of the engine itself.
3. Installing these bolt ons will create more air flow, thus a tune (more of long term fuel trim adjustment is needed to prevent your engine from going too lean) will be needed to get the "claimed" hp and tq these aftermarket companies scream about. Otherwise, your PCM on these cobalts has your long term fuel trim increased above 10% on a duty cycle (running) constantly, remember...your fuel injectors will go to adaptive strategy when needed...a tune will balance it back to 0%, that's all a tune these days really is, fuel trim adjustment on long term with obdII PCM's.
4. If your car has a Mass Air Flow Sensor (not speed density) and 02 sensor, a wideband is required by law for evap emissions control systems. Regardless what people tell you, if it has a MAF and 02, the 02 is wideband, otherwise (i.e. Honda Civics) have a Manifold Absolute Pressure sensor built into the throttle body and 02 to where a narrowband 02 sensor galvanic battery type is required. If you doubt me on this one, research your work, I test you.
5. For basic bolt ons, no need for upgrading your fuel system, unless you have upgraded internals or gone forced induction is required. Your fuel injectors work with the MAF and MAP sensors to self adjust based on environment and altitude outside of the vehicle. Upgrading your CC injectors will do nothing more than embarrass you on a n/a car with OEM internals.
I have more, but I hope this will aide you into your car building/tuning future. I want to make these clear for the average tuner to understand and also the newbies to see the real works. Most technicians at the dealerships are fixing the beginning and "know it alls" mistakes to correct the issue. HOpe this helps you guys/gals learn where the industry is as of now
---------- Post added at 04:19 PM ---------- Previous post was at 04:07 PM ----------
*bump* sorry to add this now...Honda Civic (DOHC VTEC) engines have the IAT (intake air temperature sensor) and MAP (manifold absolute pressure sensor) located between the filter to intake manifold, I apologize about that.