AjayQuickyBrown

for those who want to run "catless" this is what needs to be done to keep that pesky Check engine light off. this should work on 99 to present and is 100% revesable

Tools needed:

- 7/8" wrench or 02 remover wrench
- 2 sets of 2 18mm Spark plug non-foulers (NF for short) Napa part # 730-2442 About $7 a pack
- Drill
- 1/2" drill bit

The NFs look like this:



They are the same 18mm threads that are used for the oxygen sensors. After opening the package you will notice that the hole on the bottom of the NF is quite small. You will have to drill out the the hole larger on 2 of the NFs (1 for each side) to 1/2". Should look like this:



You will then have to remove the rear most Oxygen sensor on each side. To do so first unclip it from the harness so the wires don't get all twisted when you start threading it out. Then simply use your 7/8" (or O2 remover) and thread it out. It will probably be rusted in there and a pain to get out WD40 or some other penetrating lube should make your life easier. After removing the O2 sensor, it should go together like this, and should only go together one way. Thread the drilled out non fouler onto the o2 sensor and then the other one that was not drilled out onto the drilled out one. Should look like this:



From Left to right it goes: untouched NF, Drilled out NF, and O2 sensor.

Just repeat the steps for the other O2 sensor.

All you will then need to do is reinstall the O2 sensors into the exhaust pipe, plug them back in, and reset the computer by unhooking the battery and hooking it back up. Should look like this installed:



This mod is 100% reversible and has been working like a charm for me on my truck for about the last week. Typically after resetting my computer, for whatever reason, the SES light comes back on within 24 hours in my daily commute.

I would imagine that this will work on the 04+ models as well

Lenn

Here's my only question...

Since all F-series trucks since the early 80's have 3-way catalysts and not your conventional "single duty" cat converter, why gut it/remove it? You are actually losing performance by doing this. If you are going for sound, than great... if you like that raspy, annoying tone.

Moral of the story- If you intend on mainly doing this for sound but don't wanna lose what valuable little cajones some of our trucks have anyway, use a hi-flow cat.

AjayQuickyBrown

lenn i completely agree with you, but, for those who are going for tone, or just want to remove the rear cat to get that tone but still run the pre cats? this is for them, and as for the raspy annoying tone, some people enjoy it. and who are we to deny them this "tone" they enjoy, it is their vehicle.

deer-fear-me27

that will work but what i have done is take the check engine bulb out or tuck it behind the instrument panel... quick easy and all ya need is a screw driver... thats the redneck way lol

KC5-0

Let me make sure i am understanding. I have an 04 5.4 Screw. My truck has 4 cats. If i remove one on each side i will loose power?

AjayQuickyBrown

ya know i took mine off and felt a difference in power for the better, and sounded much better in my opinion also... i would say... DO IT

luckythirteen13

the old wives' tale that a motor needs back pressure to make power is still going around

hackersmovie

Agreed. The physics and philosophy of how an engine works is no different then they have been since they were invented. The manifold on the engine or header as it were, is enough back pressure. Anything beyond that, is ROBBING power.

2wd supercrew mudder

this is the gotts o2 mod its been a round a wile and give gotts to be me some credit

BIGRED94

Will this mod work on my 94 f150?