Catalytic Converter Help

[Big Sarge]

2000 Expedition XLT
Triton V8, 5.4L... nothing special yet (just bought it a few months ago).

Ok, so after replacing a half melted EGR sensor, EGR sensor hoses, EGR valve, flushing coolant system, replacing a radiator, hoses, and thermostat Ex runs great! (still no heat in the back when I turn the fan on full but I haven't found any threads addressing the FIX)

...30 minutes later, the Ex starts sputtering and spitting white-ish exhaust (its cold here) and it smells like rotten eggs. (bad cat I hope is the white smoke culprit, no milkshake oil thankfully)

Driver side cats are rattling like pebbles inside, o2 sensor to that cat and o2 sensor after the second cat is toast (haven't checked the pass-side cats or sensors yet).

***I don't care about emissions testing or whats legal, I am just curious if I will throw codes without a delete on the rear o2 sensors and how it will affect performance for good, bad, or ugly...HELP

Questions are:

Can I put one new cat on each side, replace all o2 sensors and just pop in some new inlets for the post-cat o2 sensors and has anyone done this?

I read on here about rear cat deletes for the o2 sensors... How do I delete them and what kind of tuner would I need?

Lastly, I am on a military single income family of 3 budget...looking for a cheap but effective solution without creating additional problems to my Ex.

Thanks in advance for any words of wisdom and experiences.



Also, it's currently throwing the infamous P0171 & P0174 codes... PCV hose and elbows felt/looked good, clean MAF sensor, I am going to clean the throttle body later and check out the PCV valve later as well...could this be from a clogged cat? Or that I put a K&N air filter on it?

 

[Big Sarge]

Anyone got any ideas yet... Pay day comes quick and I need some advice. I'll post pics of the job!

 

[GAINMOB]

you should be able to do cat delete and be fine...a lot of 97-2002 have done this with no probs...exhaust sound better and performance is felt...i have an 04 and looking to do this as well when i get duals on it

 

[walnuts4x4]

I have done a rear cat delete.... only pipe and no codes or anything and no other modifications

 

[Big Sarge]

Alright so I found some o2 sims at http://www.o2-simulators.com the ones we need on our Expys with the dual cats is the "Mini CAT CEL / MIL Fix for Vehicles 96-Current" for $85.95 (call and see about a discount-they're giving me a 10% for active duty). The way it is meant to work is you cut off your back cats, straight pipe, whatever, and you put your upflow o2 sensor before the cat or after the manifold on the pipe if you're straight piping right into the pipe like normal, then you take the sim these guys sell, screw in your o2 sensor into it and put it either after the cat or a bit further down the pipe from the first sensor if you're straight piping. Now the magic in this is that the sim they have is just that, a catalytic converter sim, it has a miniature honeycomb cat in it's housing unit so when the down flow sensor is sniffing away... all it is smelling is a good cat!

Now what setup should I use:

1. o2 - 90* cat - sim o2
-or-
2. o2 - downflow cat sim o2

Doing the job this week hopefully ($$$), I'll post pics when i do though.

***ALSO - - - Should I weld it or use the pipe clamps?

Thanks all!

 

[Big Sarge]

Oh... and YES you will need all working condition o2 sensors for this setup to work. If anyone knows of a cheaper way let me know, I heard of dummy plugs that just cap into the electrical wires hanging down off the frame in place of the plug on the wires of the o2 sensors. The only ones I found were supposedly only for GM... ?

 

[Big Sarge]

I have done a rear cat delete.... only pipe and no codes or anything and no other modifications

How will my MPG be with one cat on each side, and how is your MPG with no cats lol.... Wife is hesitant on the straight pipe idea, not a hippy about emissions but she is concerned about MPG?