CAT Cut out?
 

For a while i've been thinking about cutting the converters out from under my truck but i'm a little worried about what will happen, i know the check engine light will come on b/c it has two converters, and each has an O2 sensor behind them. I remember unplugging my mas airflow sensor the power sucked on the bottom end. would the same thing happen if i cut the cat's out from under the thing and the computer throw a very weird fuel and timing curve to compensate for it, or would the check engine light just come on? Little advise please.:U: THANKS!!!

you NEEEEED the mass air.

you DONT need cats, it will throw a code, someone that does "LS1 edit" can turn the light off. or you can get o2 sim's that trick the computer.

where could i get an o2 simulator? Ive looked all over the net for them but i cant find them

search MIL simulators. i will also search for some.

your mileage will suffer.......the truck will stay in open loop mode.....

if it gets tuned with "ls1 edit" it will help with will help the mileage and will do away with all the closed loop/open loop bs.

my cousins 5.3 truck has true dual with no cats, CAI, TB spacer, built trans ,LS1 edit then it was dyno tuned. it gets 22-23mpg on the hwy on a 235,xxx mile motor.

who could do an ls1 edit? Oh and my original engine and tranny just rolled 250000 mi yesterday.

any good performance shop that messes with camaros and corvettes will have the ls1 edit program.

they may also use another program besides ls1 edit, that does the some stuff.

when he did the edit they deleted all his egr and emissions stuff.


its crazy your stock trans is held up for over 250k

and it still gets 22-23mpg's? no egr?

yeap, thats what he said. i know the butt dyno after he got the truck tuned was CRAZY.

cool

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i just went to nelson performance's site, they say they can ship me a pcm that basically does the same thing as this "ls1 edit". it could make the current egr,rear o2 sensors, not work at all and as if they weren't even there. would this be a good idea? :humm:

That is incorrect.

REAR o2 sensors are ONLY there to give a light when the CATS are plugged.
the ECU looks at the DIFFERENCE in values from the front 2 sensors and the rear. If there is a difference in o2, the cats are WORKING. when you remove the cats. The values are very close if not the same, which throws a code.

ONLY front O2 sensors are used for FUEL mixture. If they malfunction, Open loop and default MAPS are used... also known as limp mode.

I have used ls1 edit since it first came out 8 years ago and know the LS1 inside and out.

O2 Sims are just a resister/cap that will charge and discharge the voltage from .5-.9volts for the computer to read, and your value will never match the FRONT o2 sensors, therefore not giving you check engine light.

LS1 edit is a powerful tool! You have access to EVERY TABLE, EVERY VALUE, every code. If you really mess around and NOT know what you are doing, you could turn your car into a Massive paperweight. If you KNOW what you are doing, you get MASSIVE Gains.


Cheers