Cheapest Catalytic Converter Fix
I, like many other G6 owners, encountered the problem of a failing catalytic converter and unfortunately, I did not discover this until after the 8yr/80,000 mile warranty on the catalytic. However, I fixed the problem on my own for less than $10 and only a couple hours of my time. I thought I would share with everyone my dirty little tricks. This was done on a 2007 G6 2.4 Liter
The quick version -
Hollow out the cat and create a cel eliminator using two 18mm spark plug non-foulers for the rear O2 sensor. The more detailed version is below for those who need more info.
Because the cat is part of the exhaust manifold, there is no way to make a universal fit, and the replacement is around $450. There have been many complaints about this, and for those of you who are not under warranty, cannot afford a new cat or nice headers, here is what I did:
What you will need:
1/2" sockets, deep and shallow
"Universal Joint Sockets"
1/2" Drill bit
One package of 18mm Spark plug Non-Foulers (you may have to order them from your local parts shop, they are not that common anymore, be sure to get the 18mm NOT 14mm) One pack is about $9. See attached pictures for more details on these.
1. Remove Catalytic converter, starting at the exhaust manifold. By freeing up the manifold first, you can get to the three studs at the back of the catalytic much easier. (It's still tight, but manageable)
2. Once the cat is removed, unscrew the front O2 sensor from the cat, this is important, as you will see in the next step.
3. From the back of the cat, take a punch and a hammer and clean out all of the guts. If that O2 sensor is still in, there is a chance you could hit it with the punch and that's not good. Keep in mind, hollowing out the cat will ensure that you DO NOT pass emissions if required in your state.
4. Once you have cleaned it all out, replace the front O2 sensor.
Those spark plug non-foulers are simply used as a spacer for the rear O2 sensor to "help" it get the proper emissions readings so you do not have a check engine light.
1. Drill out the center of ONE of the non-foulers using a 1/2" drill bit. This creates enough room for the O2 sensor to be seated properly.
2. Screw the drilled out non-fouler into (on top of) the other non-fouler.
3. Be sure to put the gasket on the bottom non-fouler before crawling back under the car.
1. Remember all of your gaskets and a little high-temp silicone if you have any available. I found it easiest to connect the rear of the catalytic before setting it on the manifold studs. That gave me flexibility to get those tight studs lined up. (It's probably no problem if you have 2 people, but I was alone)
2. Once everything is cinched down at the manifold and the rear, disconnect the negative battery cable, then unscrew the REAR O2 sensor, located just behind where the catalytic connects with the exhaust system.
3. I couldn't reach the plug in for the sensor so I had to fight twisting wires a little bit, but that was easier than trying to reach a plug I couldn't put my pinky on if I wanted to. I left the O2 sensor plugged in while I unscrewed it from the pipe.
4. Once the sensor is free, screw your non-foulers onto the O2 sensor.
5. Screw the O2 sensor with the non-foulers attached back into the pipe.
6. Reconnect the negative battery cable and you are all set!
Remember, this is not in compliance with emissions. Your car may run a little louder, but it is barely noticeable.
I got all of my lost power back as well as my gas mileage! And no check engine light thanks to the non-fouler trick!
Hope the post wasn't too much, just thought it might help a few more suffering from the crappy catalytics they used on these cars.[/COLOR][/B]