Iv got a 2001 F-150 V8 5.4L and I pretty much have it legally straight piped so that I will pass safety but I wanna delete 2 of my cats out. How do I do that????? In detail.

 

If the inspection does not include a sniffer, but requires a visual inspection you have two options:

Option 1 steps:
1. Cut the rear cats out.
2. Install a piece of 2.5" pipe in their place.
3. Install a O2 bung in the new piece of pipe.*
4. Use foulers or the Gotts O2 mod to avoid a CEL.

*Step 3 can be omitted by having a custom programmer that can turn off the rear O2 sensors.

Option 2 steps:

1. Remove all four cats.
2. Sell the removed cats to a scrap yard.
3. Purchase Magnaflow high flow cats
4. Install high flow cats where the front cats use to be.
5. Install a O2 bung an inch behind the high flow.
6. Install O2 sensor, it may not trigger a CEL. If it does refer to Option 1 step 4.

 

you can cut the rears take the tubing put the bungs on them and put the o2 sensors bacvk into them might need to put the resistor in line to keep CEL from coming on

 

The sniffer is the thing they put in the tail pipe right ?? And if it is than no they dont use that. But they do look under the truck so ??? If they saw I only had 2 cats instead of 4 would I fail emissions???

 

I might need to put what ??? In line

 

Yes the sniffer is what they put into the tailpipe to measure CO, NOx, etc levels. The visual depends on who your inspector is and what your local laws are.