Gibson Performance after-cat exhaust system installed in 2001 Toyota TacomaPosted in How To: Engine on April 13, 2016
After more than 326,000 miles, the factory muffler in our 2.7L-powered 2001 Toyota Tacoma 4x4 rotted out around the tailpipe. Sure, we could have just grabbed a crappy overseas replacement at our local parts store, but come on—that’s be like feeding your beloved pooch contaminated Chinese dog food full of diseased monkey brains and sawdust. Not for our beloved Tacoma, thank you. However, a quick scan of many aftermarket exhaust systems available for this truck highlighted features like huge 3-inch-diameter tubing and super-short, straight-through mufflers. In our experience these sorts of systems sound awesome behind a V-8 and pretty good behind a V-6. But put ’em behind a four-cylinder and it sounds like a suburban white kid on the mic at a rap contest—pathetic.
Based on our prior experiences with Gibson Performance’s after-cat exhaust systems, in our minds only one of the company’s in stainless steel systems featuring its Superflow mufflers would do. The Superflow mufflers are a true reverse-flow design that flows freely, yet keeps sound volumes low. Gibson does offer exhausts with large-diameter tubing and straight-through mufflers, but we selected one built entirely from stainless steel mandrel-bent 2.5-inch tubing, a polished tip, and our favorite Superflow muffler. Aluminized carbon steel systems are available but don’t feature the lifetime corrosion warranty of the stainless. Since we’re hoping to keep this Tacoma around until it hits 1,000,000 miles, the lifetime system seemed prudent.
The only fly in the ointment was that Gibson didn’t offer a direct-fit system for our particular application. The closest we could come up with in the Gibson Performance catalog was PN 618800, which is designed for a 2.7L/3.4L 2WD Tacoma. Shawn Gibson told us to come on down, and with a little cutting and some tweaks here and there, he and technician, Jack Ambriz, had little trouble fitting the 2WD system under our 4WD chassis. Now our exhaust is leak-free and we can focus on racking up those odometer miles.
Sure, you can install the Gibson Performance exhaust system at home in your driveway or garage, but we took the easy route and brought our 2001 Toyota Tacoma down to Gibson Performance’s facility in Corona, California, for photography.
You’re probably used to seeing squeaky clean, rust-free vehicles in stories like this. Not this time, bub. Our 2001 Tacoma was an east-coast 4x4 that lived right near the ocean. Even still, the O2 sensor and one of the catalytic converter bolts came out after a little soak in penetrating oil.
Gibson’s Jack Ambriz had to resort to the cutoff wheel after one of the rusted nuts rounded off in the impact socket. No worries, really, since the Gibson Performance exhaust system includes new hardware for the catalytic converter flange and the O2 sensor. It also includes all the hangers and high-quality banded clamps.
If you’re doing this at home, it’ll be much easier to cut the exhaust just aft of the muffler and remove it in two pieces, but we’re not so nice and asked Ambriz to snake our system out in one piece so we could photograph it next to the Gibson exhaust for comparison.
This is what a 15-year-old factory Toyota muffler looks like after more than 326,000 miles and 15 years of salt immersion. Not too shabby, really, but the rotted out hole was starting to get annoying and sounded like poop.
The Gibson Superflow muffler is a fully welded, reverse-flow design that’s just a tad longer than the factory muffler, but is a much smaller diameter for a cleaner fit and a bit more ground clearance from off-road obstacles. The sound is very sweet in our opinion. Just enough growl to let you know it’s a performance piece but not farty or obnoxious in the least. And when cruising at moderate throttle it’s about as quiet as stock
Nice mandrel-bent 2.5-inch-diameter tubing, stainless exhaust clamps and hangers, high-quality fasteners, and the fully welded Superflow muffler are just a few of the highlights of the Gibson Performance exhaust system. It flows a minimum of 30 percent more than the factory system and provides a noticeable seat-of-the pants improvement in acceleration and ability to maintain speed on grades.
We always love spotting a “Made in USA” stamp on any part we’re installing on one of our vehicles. Way to go, Gibson!
With the PN 618800 exhaust laid out next to the vehicle, we began by installing a new catalytic converter gasket. Gibson doesn’t include one with the system, so make sure to grab one at your local parts store. We nabbed a Fel-Pro gasket at AutoZone for a whopping $5.
Abriz bolted the head pipe to the catalytic converter and then slid the muffler over to check how it would be best clocked with the tailpipe.
Because we were fitting a 2WD system into a 4x4 for which it wasn’t designed, we wound up cutting 2 inches off the tailpipe and sliding the muffler back on the head pipe as far as we could to allow the muffler to tuck up tight to the underside of the truck. The muffler bracket worked by flipping it backwards and everything looked good and straight.
Abriz then eyeballed the tailpipe and muffler to ensure everything was level and square in the chassis before tightening any of the fasteners.
Even though it’s a bolt-in system, we chose to weld the pipes together because we had slid the muffler way back on the head pipe. We probably could have gotten away with using the supplied band clamps, but given this is an off-road 4x4 we’ll never have to worry about the two pipes separating in extreme terrain.
The O2 sensor was reinstalled in the Gibson head pipe with the supplied hardware. Be sure in all of your soaking, cutting, and working that you don’t get any contaminants on the sensor or you could find your vehicle throwing a check engine light.
The last piece of the puzzle is to install the polished stainless steel exhaust tip. It slides over the end of the tailpipe and secures with the supplied hardware.
Our Tacoma is now exhaust leak-free, gets roughly 1 mpg better fuel economy, maintains highway speeds on grades better, and best of all, it doesn’t sound like an angry Honda with a fart-can exhaust.