Removing cats on 98 5.7l

Scheidsride said:

Easy fix.. Buy some shorty headers.. The first two sensors won't be a bother.. Drop your cats an if you have two sensors after cats or one .. You can buy o2 sensor simulators.. 42 bucks a piece.. They plug into factory o2 connectors and zip tie to harness .. Make sure the county your in don't so emissions .. More power.. Better sound.. Afterthoughtsauto.com for the simulators.. Jegs or summit for the headers..

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Headers.. nah, The only headers I would run are the most expensive, and that's not in the budget, If I do take cats off, I would be interested in them there simulators asscake at the auto parts store said they didn't exist. No emissions here, I know cops around here that drive diesels with straight pipes that are chipped and I see them blowing soot all through town.

Just wanted to throw and update got some time to get the cats off today. They actually wernt clogged up with 226,000 miles on them. But gotta say it runs better notice mabye a bit of lag under 3 grand but really picks up after that whos ever under 3k anyway lol. Didnt really notice any noise change!!!!! Really was hoping it was gonna be louder but o well tones better not a lick of drone in the cab! Id say o for it if your thinking about removing them.

jcro61 said:

I personally dont think the cats being on or off will make a noticeable difference other than maybe the sound.
I always use Heddman headers, they are pretty cheap and last a decent amount of time. IMO any 500+ headers are a waste of money on a near stock truck.

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Will it have a drone sound with the cats removed? I have a 98 2500 hd 8600 and wanting to do the same thing but a few sites are saying the sound is migraine causing

Arnes98 said:

Will it have a drone sound with the cats removed? I have a 98 2500 hd 8600 and wanting to do the same thing but a few sites are saying the sound is migraine causing

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ive had my cats off for years, no cats sint gonna cause a drone, your muffler choice will. if youre gonna straight pipe it itll just be a little louder, perhaps a light drone with cruise but other then that youre fine as long as noise. also consider where your tailpipe sits and pipe size.

I have a question I've gone threw 2 cats in thr last 2 years..after the 1st one I did the head gasket upgraded the Spyder injection and put EGR valve oxygen sensors mass.air.flow sensor also the throttle positioning sensor.. And I just went threw another one.Found out today and almost all the shops around me won't work on anything 2000 or later so it's hard to find a mechanic...so it's been hell this is my only vehicle when I can't have it down for very long because I have a disabled mother and I have to take back and forth to the doctors frequently every week.. She was hit by a car...I really want.to just park it and do the build.i want in it but getting into a new vehicle has been challenging even with a 640 credit score ....can any one.Tell.me what might be my issue with burning threw cat's

Casey916 said:

I've gone threw 2 cats in thr last 2 years... ...Tell.me what might be my issue with burning threw cat's

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WHAT VEHICLE???

Generally-speaking, too much burnable fuel in the exhaust stream; which is either overly-rich mixture or--more likely--misfire.


The Usual Three:

1. Verify fuel pressure at prime, at idle, and under load. Most fuel pressure gauge assemblies have a push-button pressure release connected to crappy vinyl tubing. Route the tubing so it empties into a drain pan, then push the button while the engine is running. This simulates higher fuel demand if you can't check fuel pressure on the highway. Fuel pressure should remain steady even with fuel flowing down the pressure-relief tubing. How old is the fuel filter? Have you ever dumped a bottle of Chevron Techron Complete Fuel System Cleaner into the gas tank? (Recommended at every oil change.)
   
2. How old are the usual “tune-up” parts and procedures? Inspect/replace distributor cap, rotor, plug wires, spark plugs. Make sure the ignition coil will reliably fire a spark-tester calibrated for HEI when the coil is fully warm, and misted with water from a squirt-bottle. Cranking compression test of all cylinders while the spark plugs are removed. Verify EGR, PCV, EVAP, and Heated Air Intake (if used) systems for proper operation. Verify proper initial timing (TBI) and electronic spark advance (TBI and Vortec). Replace old O2 sensors unless you can PROVE that they're working properly—old O2 sensors get lazy, they don't provide accurate data, but they do provide “data” that fools people into thinking they're “working”.
   
3. Connect a scan tool (NOT a crappy “code reader”) and look for “codes”. More important, look at the data stream to verify EVERY sensor and computer output. Verify fuel trims during the time that the vehicle is not running properly. Look for misfire counts for each cylinder (OBD2 only.) “Codes” have official diagnostic procedures that will be found in the service manual set for your vehicle. The service manual set can be downloaded from the links in the Sticky thread section of the Engine forum on this web site.

I will also add oil burning is an easy way to kill a catalytic converter.