29 replies to this topic

[Mugs]

Ok so I am going to try the anti fouler trick. Allready replaced the rear O2 and was good for about a month.

It was mentioned that one needs to drill out the anti fouler for the O2 to fit (I havee allready bought the parts and confirmed this).

So my question is this: Do I drill it out just enough for the O2 "nozzle" to fit into the fouler and leave the small hole at the end still intact. Or do I drill the whole thing through and have it be one big opening?

Thanks in advance.
Doug.

[johnceggleston]

Ok so I am going to try the anti fouler trick. Allready replaced the rear O2 and was good for about a month.

It was mentioned that one needs to drill out the anti fouler for the O2 to fit (I havee allready bought the parts and confirmed this).

So my question is this: Do I drill it out just enough for the O2 "nozzle" to fit into the fouler and leave the small hole at the end still intact. Or do I drill the whole thing through and have it be one big opening?

Thanks in advance.
Doug.

the pics i have seen show 2 anti foulers used on the rear, the first one , threaded into the exhaust is left in tact, no changes. the second one , threaded into the first is drilled through completely. it appears as thought the tip of the o2 is longer than the anti-fouler so it extends part way into the first one. this setup puts the o2 sensor in its own small compartment with a very small opening into the exhaust .

please correct me if i'm wrong.

[GeneralDisorder]

When I've done it I only use one - drilled completely through. Works fine.

GD

[johnceggleston]

When I've done it I only use one - drilled completely through. Works fine.

GD

that would certainly make it easier to mount, clearance wise.

[WoodsWagon]

1/2" drill bit is the one to use. Drill one all the way through, and it leaves the tip of the 02 sensor flush with the end of the anti-fouler.

Stacking 2 is a waste of time, I've seen cars with NO cats working fine with just one.

Replace the front 02 sensor while you're there, if you did the rear one, the front one's not far behind. Potentially better MPG and cleaner running could result.

[subaru360]

I use 2. I leave the one that screws into the exhaust pipe intact. I drill the second one out all the way.

[Mugs]

Replace the front 02 sensor while you're there, if you did the rear one, the front one's not far behind. Potentially better MPG and cleaner running could result.

This is in hopes that it will fix the re-accuring 420 code. It is for a "customer" and since he allready paid me for the O2 job I am throwing this in as a freebee. So I don't want to replace the front unless that code pops.

MPG and clean emissions is not a problem with it...yet.

[Nbe1210]

I'm about to set this up on my 97 legacy this weekend. Does anyone know what size anti fouler to get? I can't tell without taking the sensor out and I would like to do this in one swoop. Thanks for any help

[davebugs]

There are 2 sizes, you want the smaller one - the same size as a spark plug.

Perhaps someone remembers the size, I think it's 17mm.

They come 2 to a package.

[J A Blazer]

I think the size is 18 mm.

[brus brother]

http://www.autozone....ier=730544_0_0_
18mm is the size. Above is the link to Autozone part. Comes 2 in a pack for about $5.
NOTE: As I and others have discovered, this doesn't work on MY 2005+

[Nbe1210]

I searched through all the sensors on the Autozone website and found a few that listed the thread width as 18mm. I guess I'll go with that since it agrees with the sentiment here. Thanks for the help and if it turns out to be a different size I will certainly post it here.

[hohieu]

Definitely 18mm. Spark plugs sizes are either 14mm or 18 mm. I think the only question is whether you want to get the shorter or longer anti-fouler -- either one will work.

[WoodsWagon]

Make sure it's a flat washer anti-fouler, they sell tapered ones too.
18mm flat washer anti-fouler Help brand 42009

[GeneralDisorder]

I stock these for "off road and racing purposes" :cool:

http://www.ebay.com/...aac418c&vxp=mtr

They work better, fit better, and no drilling involved. Much easier for me.



GD

[Nbe1210]

I just finished installing the anti fouler on the down stream sensor in my 97 legacy brighton. Some tips that I wish I knew before.

-The sensor requires a 22mm wrench to remove/reinstall. I didn't trust my adjustable at the weird angle so I went and bought 3 different sizes 20-22mm. I got lucky that i got the right one and saved another trip.

-a little penetrant and it came right off. Lucky me I guess. My Tacoma o2 sensor was not that easy a few years ago

-After I got it loose i went to unplug from under the hood and saw that I could reach the sensor easy as could be from above instead of wrapping my arm around the exhaust pipe. Shame on me for not looking. It went back in a lot easier.

I have a drill press and the anti fouler was cake to drill through.




I'm driving to MA for a wedding tomorrow so we'll see if it worked. I'll update with the results and thanks for all the help


Update: I started the car a few hours after posting the above and check engine light was on. I had the negative terminal disconnected for about 10 minutes. Shouldn't the computer reset and clear all the codes? Did I do something wrong? Thanks for any help.

Edited by Nbe1210, 06 October 2012 - 03:01 PM.

[brus brother]

Stop by Autozone and have them clear the code for you.
The car will run a little wonky while the computer relearns.
It will take a few driving cycles for all of the systems to become ready but hopefully that will be the end of your 0420 light show.

[Nbe1210]

I went to advanced auto and they said they are not allowed to clear codes so I did the old disconnect the battery for a while and turn the key a few times trick. It worked this time and the light has not come back on yet. My wife is taking the car for a 3 hour trip tomorrow so that will be the true test.
I also just replaced the front o2 sensor with a new Bosch sensor I found on amazon fo $50. The sensor that came out of the car was a bosch so i stuck with that brand. I was able get at it through the open hood and did not have to lift the car. This one was tougher to get out. I ended up running the car for 2-3 minutes to heat it up and it came loose. The whole job took all of 25 minutes. Hopefully the car will be happy and continue to go for years. Thanks to all for the help with this little job. I'm learning new stuff all the time.

[brus brother]

I use:
MaxiScan MS300 OBD2/OBDII Car Auto Diagnostic Code Reader Scanner Tool CAN$22 shipped on ebay.
Pretty basic but it: Reads and erases codes.
Tells you if systems are "ready" if you are trying to sneak by emissions testing.

[J A Blazer]

Question: I'm getting ready to do this and have drilled an anti-fouler to 1/2 ". However, a test fit with an old up-stream O2 sensor reveals that 1/2" is NOT enough. Is the downstream O2 sensor (which I have not yet removed or I would have done the test-fit with it) slightly smaller in diameter? TIA.

[Nbe1210]

In my 97 legacy they looked like exactly the same sensors just different shaped plugs at the electrical connectors. The upstream connector that I did today was a triangle plug and the downstream had a square plug. Otherwise exactly the same. I used a 1/2 inch bit and it worked perfect just a week or two ago. Good luck

[johnceggleston]

+1^ what he said.

[GeneralDisorder]

Some aftermarket sensors are larger than 1/2".

Yet another reason I use the eBay L shaped sensor spacers - they accommodate all sensors and are more effective both in fitment and in not requiring a second non-fouler as occasionally a single one isn't enough. $8 for two non-foulers that I have to drill out and mess with and fit poorly or $16 free shipping for the right part.... You do the math.

GD

[J A Blazer]

The L-shaped one is looking better and better.

[Nbe1210]

The L shaped fitting looks nice. My only concern would be whether there is enough space for the sensor to fit. Of the two sensors I recently work with I think the back would not fit and the front would but only if the L was pointing in the right direction.
I think it would be worth a good look at your sensor locations before ordering. I replaced the front with a new Bosch sensor but I don't think a non fouler would have fit in that space so the L would have to be the right fitting there. I don't know if it would do anything on the front sensor though.
Also, the non fouler I used must have been aluminum because it drilled like butter. Took all of a minute.