Just curious. when you gut your cats, what is it that gives you the SES light? I just drilled bout 10 holes thru the insides of the cats and dont seem to be getting a SES light yet. Will i get one maybe after it adjusts to the new headers and change in cat flow, or do yall think i'll be ok and not get a light?

Tell me what yall think,

Thanks guys

 

It's the oxygen sensors that give the SES lights. They are constantly monitoring your air/fuel ratio and try to get near the perfect 14.7 parts of air to 1 part of fuel (14.7:1). If any change is detected it will throw a code sensing that the motor is running rich or lean. If I remember correctly, it sends a .9 volts for rich and .1 volts for a lean condition to the PCM. I do not know if this will affect motor performance by the PCM altering air/fuel flow. You drilled holes in the cat? That's not going to do any good and it will cause naughsiating(sp?) headaches for exhaust fumes coming into the cab. To properly gut a cat your much remove it from the exhaust and scrape all absorbing beads and honey comb filter out. You have to get a new tune on the PCM for your engine to stop throwing the SES codes. I have heard from many people the 02 sensor bungs that "trick" the PCM into believing the cats are there or not gutted do not work, but for a couple hundred miles.
Philip S.

 

Nah, not from the outside. I dont plan on sucking up raw gas. I took the stock y pipe off. cut it back some where the lt headers would fit and then drilled holes straight thru the cats. So in other words, none of the outside tubing was effected. shitload of powder or sand.(no clue?) came out. I then created a sand castle and soon got back to work. I have an air compressor and blasted the hell outta the cats and you could definetly tell an increase in air flow. I didn't wanna completely gut the cats, mainly because i was hoping drilling them wouldn't screw up the a/f ratio and send codes. Also dont wanna get that rasp sound once the muffler goes on

Thank you for your information though. I ordered a set of o2 sims, but they dont seem to fit, im guessin there the wrong ones and plan on sending them back. Either i could get a new set or try and get my money back and go ahead and get a tune and delete the sensors all together.

 

seems to me that the inside honeycomb stuff will begin to come apart and go through the muff. maybe not. i had my pcm tuned for no cats.

 

i need to do that next

 

going from cats to no cats is a big diff.

 

Just from my input as I mentioned before, the 02 sims do not work. They work for about 100-200 miles and then the lights come on again. Getting a new tune for no catylitic converters is the best thing to do. Your welcome on the info, anytime!
Philip S.