I’m going to try to make this review as comprehensive as possible, so for any other DIY’ers out there gaining knowledge, this will help you out. First of all, these headers are the best performance boost you could do your car. People start with intake, because its cheap, and exhausts second because it sound cool, but if you want a bump in your seat, get headers first. I slapped these puppies on then took them on a 700 mile road trip cross state, and BOY!!!, I was in love with how they make the throttle response so much more engaged. The reason for a 4 star and not 5 is....I wish these were stainless like the other headers they offer. Sucks that mild steel last shorter than stainless because I already have a thought of replacing them with long tubes if I get a supercharger, however I do know the steel is thick and strong AF because of the second reason..Number 2...please for the love of HorsePower JESUS DRILL OUT THE MOUNTING HOLES BIGGER THAN JUST THE SCREW SIZE. First time I try to fit them on, they don’t fit on all the studs I just tourqued to spec, because the holes were too “precise”. I eventually put them on with out two nuts and stud (get new nuts and studs, I’ll get to that in a sec), BUT I couldn’t rev about 5k without rattling my gasket and causing a vacuum leak, yet I still took it over 700 miles and it still galloped like a champion. The build quality is great even being paint treated steel (which cause quite the burn off on first start), I used up, two drill bits, drilling out the holes today, and I found out I cross threaded two studs installing it the first time.....yeah being a DIYer is great, but you learn and that’s what better. I learned a lot doing this. If your a DIYer, headers are up there with a belt change, It’s an absolute PITA and I did This in an apt parking lot, no F’s given... anyway this setup doesn’t come with a new gasket like the other two headers..,it doesn’t come with a lot of things you really should replace as well, but ZZP does offer everything separately in other categories, if you can still get them in stock. Here’s what I got with this setup to do it right:
-Exhaust nuts and studs
-Angled **** (headers can cause CEL, no no for emissions, however this **** also threw a CEL for the first week then went away so idk bout this one)
-02 **** plug
Get the second 02 ****, then get a plug for it. If you want to tune your rig, and trust me, you do....then your going to want a wideband o2 sensor, and you don’t want to use a stock location because its a PITA to tune around, so choke up the extra dough and get a proper tune to get that boom boom. Also make sure you have a breaker bar and plenty of PB blaster. Taking off rusted **** is almost as fun as trying to fit on, brand new precise stuff with tight clearances. Also make sure you got a tourque wrench and a proper torx socket for them studs..ask me how I know how much aluminum sucks to rub off and cross thread......I’m sure I missed something, I been thinking about this obviously because my cobalt is my baby, and I really feel ZZP is where I will go for all my parts from now on. I’m building a street sweeper all thanks to ZZPs awesome parts. So do your research and be prepared to spend a bit more than you thought, but make sure you do it right and don’t blame ZZP for things for didn’t know or prepare for. And you will have the boom boom too. Sound with stock cat back is throaty but muted, I want it louder so obviously I’m getting the 2.5 catback, but for anyone tossing up which one to do, without ******* off the neighbors, do this first....its so worth it...all the blood, sweat and tears, are so.....worth....it....see you on the streets.
Specs: 2009 Chevy cobalt, 2.2 manual. No secondary air injection. Mods: DIY Spectre intake, mid length header/ downpipe combo, Next mods= 2.5 catback, hp tune. Short throw shifter, Supercharger? (Skys the limit till I blow the engine haha)