Just wanted to do a "post-install" report for you guys, in case anyone's interested: I removed the stock exhaust and installed the Magnaflow catback on Saturday morning. Yes, you will need to cut the factory exhaust behind the stock muffler. I chose to cut it a few inches behind the muffler, for ease of re-installation (mainly for ease of welding room) when I turn it back in at lease end. Cutting it farther towards the rear would make easier to remove, as you must snake the rear portion up and over the axle/spare tire, etc...it was not that difficult, just requires a bit of finesse (and a few swear words for good measure!) Keep in mind, all of this was done in the driveway, with the rear of the Tahoe up on some car ramps for a little extra room. The biggest obstacle was getting the rubber isolator bushings off, but using some large channel locks, I figured it out and the rest came off pretty easy (take care not to ruin them, or you'll have to go to Chevy and get more)
Installation of the Magnaflow was real easy. Start at front and work your way back...tighten just enough to keep it together, then make adjustments to get the tip situated correctly and clearance for all tubing. The tubes were perfectly bent, it clears with plenty of room. The tip was a tad too close after my first test drive, it came to rest about 1/4 inch from the body. I went back under and adjusted the rear section, and now is perfect. The band clamps they use are high quality, way better than the old u-bolts...too bad the muffler is out of sight under there, as the polished stainless looks sweet.
Anyways, it took me about an hour from start to finish, most of the time to remove the factory system. I'm sure if you had an extra set of hands, you could shave a little time off. It sounds really good, has a nice deep rumble at startup and acceleration. It does NOT drone at all while cruising, you just hear a tad more rumble (very pleasing to the ear)...and sounds like a truck should when you hit the gas. I'm very happy with it. High quality build, should last a long time. I can't hear any big difference in the 4 cylinder mode (but I have never been accused of great hearing anyways!)
Tools needed: Sawzall (to make the cut on the factory system), 15mm socket wrench, and a torque wrench if you want to get technical (they call for 65ft-lbs on the bands). I did NOT disconnect the battery terminal during or after the install...truck runs fine, no change in idle or anything. I'm sure it is mostly the enhanced sound playing tricks, but it does feel a little more responsive just off idle...haven't driven far enough to see if fuel mileage is affected (plus, I keep gassing it to hear the exhaust!) I'll monitor over the next few fill ups to see if any change.
For the computer tuning guys - should I disconnect the battery to get the computer to relearn? Or will it re-learn on its own? I was hoping to avoid having to reset all of the electronics if I could...
