This is part of a supercharger build I have in another thread. Felt the information might be helpful to someone else in the future. Here is the start of the project today.

Installation of ZZP Full length header, cat pipe, and 3' tail pipe with no resonator.

Parts required:Removal and installation time: 2.5 hours

Tools required: skunk piss (WD-40), 15mm socket and ratchet, hacksaw, impact, 13mm deep socket, torque wrench, 13/16 O2 wrench, anti-sieze, screwdriver, c-clamp, lift or a jack on driver's side rear with safety jack.

Remove 2 cat back nuts just after catalytic converter. Remove 2 rear muffler rubber grommets and progress towards front of car removing 2 more. Cut tailpipe just in front of rear axle where it is straight and flat. This is an easy spot to weld and or reassemble should the pipe be usable on another car. Slide out muffler assembly from axle.

Install muffler by attaching to grommets. Install 2 curved bent pipes over axle with band clamps. Leave band clamps loose so that it can be adjusted. Do not install cat-back just yet.

I am not sure what is up with the pictures, but if you right click and 'open in new tab', it works. Maybe someone can chime in. I am too busy to troubleshoot this right now.



Remove air filter box by loosing two hose clamps, remove air filter bracket (2 bolts), remove exhaust heat shield (3 bolts), unhook 02 sensor wires and remove out of heat shield, remove 10 exhaust manifold nuts. Slide manifold all the way down to allow removal of catalytic converter from exhaust manifold (3 bolts), remove exhaust manifold from car out the top. Remove both O2 sensors- note which O2 sensor was closest to the header. Make sure exhaust gasket is removed from cylinder head. Clean up exhaust manifold with parts cleaner.



Install both O2 sensors- don't forget to put anti-seize in the threads and locate the correct sensor to the correct locations in the new pipes. Install the exhaust gasket onto the cylinder head studs- black side facing out. Install long tube header from the top. Install all 10 nuts and torque to 9ft lbs. Start in the center and work outward. Install CAT pipe and band clamp. Use a long Clamp to pre-clamp band clamp into place and start the nut. Install CAT back pipe and gasket. Don't forget to put anti-seize on all of the band clamps and bolts. Tighten and align the exhaust. Hook up O2 wires and wire tie any out of the way. Test for noises.

Comments: Over all good kit with quality construction. No modifications were necessary and everything bolted right up. Very loud drone at highway speeds. I will be ordering the resonator pipe to see if this helps. If it does not, I will be cutting the muffler off and installing a 3" 3 chamber muffler.

 

That header package you have is really nice.

Been down that road. A full header back exhaust drones really bad. I even ordered the resonator and put on a chambered muffler. Finally said F that and threw the stock cat-back back on and enjoyed the performance/sound from the header/downpipe. I think I have high NVH tolerance too!

 

That's what worries me and why I keep delaying the header/downpipe..I don't want that noise or drone..
Anyone have any videos/soudclips of a new header/downpipe combo with a cat-back exhaust that they can share?? :)

 

Sure, I have a vid with the zzp combo after I switched to the cobalt ss/sc exhaust. It's noticeably louder. With the stock hhr catback it was just a tiny bit louder than stock, but had a rhythm more like a the v6 from a grand prix, I liked it.

 

Sorry for the delay. I now have installed the full length header, cat, resonator, and muffler from ZZP. They hit me up for another $190 for the resonator section. It is a full stainless 24 inch version and well constructed. The drone is gone completely. I only hear the car running when under throttle. This means when under throttle to scale a hill, you can hear the exhaust, but not a drone. It sounds like an small engine airplane flying past overhead and it is low enough to handle cell phone calls to.

I did have to clearance the pipe just over the axle where the exhaust hanger is welded to the chassis. It had a tendency to vibrate against it on cold mornings. I could not go the other direction with it as it would hit the gas tank. I also had to heat the driver's side muffler strap and bend it to the correct angle to keep it from hitting the frame as well. All in all, I am very satisfied with the $1,000 plus purchase. Time to add the supercharger!

 

Status update:
With CAT, Resonator, and muffler the drone in the cabin is excessive when under load at 50 mph plus. I even tried one of those cheesy tail pipe inserts- no change in the drone.

Also, after 150 miles of driving, the O2 Sensor lightup and provides a P0420 code. A reset of the code will make it go away, but comes right back after 150 miles. I may need to tune this problem out. Just providing a heads up if someone wants to upgrade and expects no computer problems.

 

Status update: I purchased a cheap aluminized steel Walker Exhaust 18160 muffler to replace my stainless Magnaflow and tip. It barely fits within the space of the ZZP CAT Back kit and I had to turn it at an angle to clear the plastic fender well. What a difference in the sound. It went from sounding like no muffler to somewhat of a muscle car idle which cackles when hitting WOT. Very nice sound that is pleasant to hear and not over-powering.

Magnaflow muffler: 88 decibels at an idle inside the car.
New muffler: 79 decibels inside the car.

Major difference is the drone the car had outside and inside the car at an idle and at highway speed. A decibel meter will not catch this. However, the drone was so bad that it sounded like no muffler. This muffler has a housing that is 20" long versus 14".

 

Nice info write up thanks for sharing..