Jeff4runner
New member
Possible sticky? I didnt notice this on the list of common repairs, etc.
Well, I honestly cant say why my cats (both) went out a few months ago. Bad fuel, seafoam, octane booster, or just my driving, who knows?
Well, I got sick of the annoying light, and the decrease in gas mileage. After reading several other fixes, and alot of experimentation, I thought Id post soemthing on it. Heres what you can do to fix it, if both sides are failing/gone. If its only one side, you are lucky and only need to pay $5.
Go to advance auto parts . com, and order the Dorman - Help Spark Plug Non-foulers part no. 42009. They come 2 to a pack, and you'll combine them into one tube. If you order online, you can take the weekly discount of 20% off, or something (look on dealnews . com under advance auto). This will bring it to about $5. Order two of them, and you have 2 sets for each post-cat O2 sensor.
Take one of the two non-foulers, and place it in a vice grip/bench vice. If you have a drill press, this will be very easy. Otherwise, you need a very good electric drill, and a hardened steel/diamond tip 1/2 inch drill bit, or a really good metal-drilling bit. Drill a hole down the center of the non-fouler with the outside threads facing down. In other words, drill it from the top opening. Be sure to have someone use a really good lubricant or some oil while drilling. It will smoke and heat up fast.
Next, take the second non-fouler, and drill a 3/8th-7/16th hole the same way as the first. Screw in the first non fouler into the second, so the 1/2 inch hole is closest to the top, and the 3/8th hole is on the bottom. The 1/2 inch hole is room for the O2 sensor tip to fit inside the non-fouler, and the 3/8th hole is to allow a small amount of exhaust flow so the computer still reads properly.
Finally, place the car on a lift or jack the front up. Put it on jackstands about a foot higher than normal so you can maneuver underneath. If you are brave, do this while the exhaust is still at operating temperature, because the metal has expanded and the threads loosen easier. Otherwise, allow the pipe to cool completely, and soak it in PB blaster. Once you are ready, take an O2 socket, or a wrench of that size, and slowly unscrew the O2 sensor. It should need one good yank, and then you can unscrew it easily by hand (wear gloves if hot. I learned the hard way, lol). If it still feels snug after unscrewing it a bit, then its possible they are stripped. Stop, and screw it back in just firmly. Then, take it to get fixed (or fix it yourself, either way.).
After you removed the sensor, screw it into the tube/spacer of the 2 non-foulers. If it doesnt fit, make sure you have the 1/2 inch hole on the top, or try re-drilling it straighter. You want a pretty decent gap between the walls of the non fouler, and the sensor tip. Screw the sensor into the spacer at factory torque (I did about 25 ft lbs), and screw in the sensor/spacer assembly to the exhaust hole you took it out of. If it wont go in, dont force it. Try figuring out what is wrong (hopefully it wont be too bad). Torque the spacer into the exhaust to factory torque, and reattach the wiring harness to the plug.
Repeat the process to the other side (same exact) if you have 2 bad cats. After finishing, start the car, and go test it. Dont be alarmed if it starts hard or different, then idles very low (400-500 rpm). Give it 10 seconds, and the exhaust will be able to go in to the spacer, and trick the computer into thinking it is still reading flow. I had the problem of low idle for a long time, so thats how I determined to drill the second hole into the bottom spacer (the one that goes in the pipe). If it does still idle low, give it a few minutes of good driving to warm up, and allow the computer to adapt to the abnormal flow readings. It isnt enough to throw a code, but it still fools the computer to thinking the catalytic converter is still working. I did this mod 2 weeks ago, and still no check engine light to be found. This either means it works, or the catalytic converter self-diagnostic went out (not likely, since that would throw a code itself). Overall, very happy this works, and it saved me 500$ in new cats.
I will post pics of the spacer on the pipe, but its not really much to look at. Just 2 non-foulers stacked on the pipe with the O2 sensor.
****Disclaimer**** I am an ASE Certified technician, and I highly advise against doing this yourself. I take no responsibility for what hazards you may pose to your health, or damages to your vehicle. This is for educational purposes only that I took from experience, and advise against doing this at home. Take your car to a qualified mechanic, or only do this repair if you are mechanically competent, and can be responsible for damages to your vehicle.
Well, I honestly cant say why my cats (both) went out a few months ago. Bad fuel, seafoam, octane booster, or just my driving, who knows?
Well, I got sick of the annoying light, and the decrease in gas mileage. After reading several other fixes, and alot of experimentation, I thought Id post soemthing on it. Heres what you can do to fix it, if both sides are failing/gone. If its only one side, you are lucky and only need to pay $5.
Go to advance auto parts . com, and order the Dorman - Help Spark Plug Non-foulers part no. 42009. They come 2 to a pack, and you'll combine them into one tube. If you order online, you can take the weekly discount of 20% off, or something (look on dealnews . com under advance auto). This will bring it to about $5. Order two of them, and you have 2 sets for each post-cat O2 sensor.
Take one of the two non-foulers, and place it in a vice grip/bench vice. If you have a drill press, this will be very easy. Otherwise, you need a very good electric drill, and a hardened steel/diamond tip 1/2 inch drill bit, or a really good metal-drilling bit. Drill a hole down the center of the non-fouler with the outside threads facing down. In other words, drill it from the top opening. Be sure to have someone use a really good lubricant or some oil while drilling. It will smoke and heat up fast.
Next, take the second non-fouler, and drill a 3/8th-7/16th hole the same way as the first. Screw in the first non fouler into the second, so the 1/2 inch hole is closest to the top, and the 3/8th hole is on the bottom. The 1/2 inch hole is room for the O2 sensor tip to fit inside the non-fouler, and the 3/8th hole is to allow a small amount of exhaust flow so the computer still reads properly.
Finally, place the car on a lift or jack the front up. Put it on jackstands about a foot higher than normal so you can maneuver underneath. If you are brave, do this while the exhaust is still at operating temperature, because the metal has expanded and the threads loosen easier. Otherwise, allow the pipe to cool completely, and soak it in PB blaster. Once you are ready, take an O2 socket, or a wrench of that size, and slowly unscrew the O2 sensor. It should need one good yank, and then you can unscrew it easily by hand (wear gloves if hot. I learned the hard way, lol). If it still feels snug after unscrewing it a bit, then its possible they are stripped. Stop, and screw it back in just firmly. Then, take it to get fixed (or fix it yourself, either way.).
After you removed the sensor, screw it into the tube/spacer of the 2 non-foulers. If it doesnt fit, make sure you have the 1/2 inch hole on the top, or try re-drilling it straighter. You want a pretty decent gap between the walls of the non fouler, and the sensor tip. Screw the sensor into the spacer at factory torque (I did about 25 ft lbs), and screw in the sensor/spacer assembly to the exhaust hole you took it out of. If it wont go in, dont force it. Try figuring out what is wrong (hopefully it wont be too bad). Torque the spacer into the exhaust to factory torque, and reattach the wiring harness to the plug.
Repeat the process to the other side (same exact) if you have 2 bad cats. After finishing, start the car, and go test it. Dont be alarmed if it starts hard or different, then idles very low (400-500 rpm). Give it 10 seconds, and the exhaust will be able to go in to the spacer, and trick the computer into thinking it is still reading flow. I had the problem of low idle for a long time, so thats how I determined to drill the second hole into the bottom spacer (the one that goes in the pipe). If it does still idle low, give it a few minutes of good driving to warm up, and allow the computer to adapt to the abnormal flow readings. It isnt enough to throw a code, but it still fools the computer to thinking the catalytic converter is still working. I did this mod 2 weeks ago, and still no check engine light to be found. This either means it works, or the catalytic converter self-diagnostic went out (not likely, since that would throw a code itself). Overall, very happy this works, and it saved me 500$ in new cats.
I will post pics of the spacer on the pipe, but its not really much to look at. Just 2 non-foulers stacked on the pipe with the O2 sensor.
****Disclaimer**** I am an ASE Certified technician, and I highly advise against doing this yourself. I take no responsibility for what hazards you may pose to your health, or damages to your vehicle. This is for educational purposes only that I took from experience, and advise against doing this at home. Take your car to a qualified mechanic, or only do this repair if you are mechanically competent, and can be responsible for damages to your vehicle.
