Installing The Bonez SuperFlo Catalytic Converter

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Exhaust work is the easiest thing you can do to a car to improve performance. Opening up the exhaust results in less back pressure and a greater flow allowing more air and fuel to go through the engine. This makes more power. If you would like to open up your exhaust and remain emissions compliant, one of your choices is the Bonez SuperFlo catalytic converter system from Rotary Performance. This is a high flow catalytic converter that is less restrictive than most mufflers which also includes a downpipe and presilencer. These replace the restrictive stock precats. With this unit there is no excuse to run a straight pipe. And it will open your 5th and 6th ports, thus maintaining your top end power.

Usually working with the exhaust is rather straightforward. The only part you really have to be concerned with his rust. Because the exhaust system is situated close to the ground and subject to great heat, rust is common. This is especially true in snowy climates where salt is used. The best advice regarding with rust is to use lots of penetrating lube. Use penetrating lube day or two before you begin and reapply every few hours to loosen up stuck bolts. Most likely, you will break off a bolt or two, but don't worry about it as exhaust parts are cheap and easy to find.

Parts Required

Step 1 - Lift the car
The easiest way I've found lift a car for the home mechanic is to simply use jacks and jack stands. Use the jacks two lift the car and set it on jack stands. The jack stands should be positioned under heavy frame members such as engine crossmembers, the rear differential brace or the differential itself. Do not used regular jacks to support the car will you are under it as doing so is just an invitation to be crushed. Car ramps can also be used but can be more awkward to set up, especially if you are lacking floor jack.
Step 2 - Remove the split air tube
The replacement catalytic converter does not come with an flange for the split air pipe. Therefore you'll have to cut off the stock flange and use the small piece of rubber tubing supplied with the new catalytic converter to join the existing split air pipe and the nipple on the catalytic converter. Use a small pipe cutter to remove the flange from the split air pipe about an inch away from the connection.
Step 3 - Remove bolts
Use a socket wrench and/or breaker bar to remove the bolts that connect the cat to the rest of the exhaust system. These bolts will often rust so they may take some creative measures to remove. If all else fails use an angle grinder to grind them off as you will not need them for installation of the new catalytic converter. Now remove the bolts that hold the catalytic converter to the manifold. You have to remove the heat shield first. As with all exhaust components the heat shield bolts will most likely be rusted in place and will most likely break off. Don't worry about this is she shields not required component. If the manifold to cat bolts break off or are otherwise damaged, remove them completely and use new bolts in the holes on the manifold flange. You will need bolts about two inches long, and lock washers are a necessity.
Step 4 - Remove old, install new
At this point, the old catalytic converter system should fall off. If it doesn't, it may take a few well placed blows with a mallette to remove. For disposal of the old system, contact a local toxic waste disposal company to check local laws. They may require the old cat be given special treatment. Intallation of the new system is really a two person job. Someone will have to hold the unit up while you attach the manifold bolts and snug them down. Don't tighten them yet. With the unit hanging off the manifold, bolt up the cat-back part of the system, leaving the bolts snug. With everything lined up, tighten down all the bolts. Be sure to clean all the exhaust flanges before you bolt up the system to prevent leaks.
Step 5 - Connect the split air pipe
Slide one of the supplied hose clips up the split air pipe a few inches, and place the other one over the nipple on the new catalitic converter. Push the supplied rubber hose over both ends, slide on the hose clamps and then tighten. Don't overtighten the clamps as that wil cut the high temperature hose, leading to failure and an annoying exhaust leak.
Step 6 - Test
Start the car and check for exhaust leaks. If there are any, rectify the problem before continuing. Usually, this is caused by a loose bolt or bad gasket seal.
Step 7 - Reassemble and lower the car
Reinstall all the heat shields that were removed and lower the car.


1. The new catalytic converter may smell strange for a week or so. This is normal as the system is breaking in.

2. If you are replacing a horribly clogged converter, fix the problem that caused the clogging first. Otherwise, you will very soon clog the new unit.

3. You don't have to replace the gaskets, but doing so is a good idea as they are cheap and using new ones will minimize the possibility of leaks.

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