hello all...this is my first post here..i dont own a blazer im posting for my friend who owns a 2001 blazer extreme. hes got a few bolt ons..but recently his Cat is gettting really clogged up and smells like crap when we get out on the highwy or driving hard.

so hes gona get the cat cut out and get a straihgt pipe welded in place

my quiestion is where should we go to get a mil eliminator for the 02 sensor after hes got this done...so he doesnt get a CEL??


i dont know if you can use any MIL eliminator or not..

any help would be greatly appreciated!

thanks!

 

Well, this is ILLEGAL. Ok so now that I have said that, it is EXTREMELY UNRESPONSIBLE to run without a catalytic converter. Not to mention that NO shop near you will do the work he requires. Why would they when the risk their very existence by doing so. I can make a cool $500 if he lives in the states just by turning you in (so can anyone that knows him).

Ok, so you state that the cat needs replacing. So REPLACE it. Good high flow units will more than outflow even a heavily modified 4.3L. Even with an aftermarket high flow cat, you may still get a CEL. So an O2 sensor sim may still be necessary. I only know where to get one for the 3800 v6, but I'm sure that one can be found for the 4.3L v6. Another option would be a custom PCM with the B1S2 (and/or B1S3) codes deleted.

For reference, I know of many 3800 S2 L67s that are over 400chp and still running a cat. I have yet to see a 400chp 4.3L not on the bottle. You're looking for improvements where none (or next to none) can be had. Sure, the difference between his clogged cat and a straight pipe would be huge, but there is next to no difference between that straight pipe and a good aftermarket cat.

I suggest he do the responsible thing and replace his partially clogged cat with a suitable aftermarket high flow unit.

 

im one of the people who dont really care if someone runs a cat or not... to be honest. but! you should know that if you are going to replace the cat dont be fooled into getting a "high flow cat" they arent any more high flowing than the cats we have stock In actuality, the newer cats will outflow some of the best known high performance mufflers!!! Its restriction is around 1/3 inch of pressure which is far less than the number one used aftermarket muffler system, which is over 1 inch pressure, If your worrying about flow, dont attack the cat and believe the hype, watch you muffler choices. You want 275CFM flow or better to not restrict the pipe allowances at 2 1/4 + with bends,

The only way to plug a new cat is by running so rich it melts the plates, or oil soak them shut. Either of these scenarios are good for power anyhow and signal a problem that needs addressing!

 

Yes, very true, unless you increase the exhaust size, then you have to go with an aftermarket cat. I do agree that 'highflow' doesn't mean higher flow than stock, but many aftermarket cats can be purchased for under $50. All of my experience with cats and aftermarket cats has been on 3800 v6s and you typically will install an aftermarket cat when you do headers because the headers (w/ downpipe) have a larger size (2.5" stock vs 3" w/ headers).

 

well i found a mil eliminator on ebay

it says it will work on any GM after 1995

EBAY MIL Eliminator

for anyone who is interested, since i saw a few post about this already on here

 

Good luck with that. Their statements alone on how the O2 sensors get used in todays engines is enough for me to walk away. In no way will a downstream sensor (B1S2 and/or B1S3) cause any difference to the fuel system.

In engines with 2 banks (aka v6,v8,etc), O2 sensor systems with 3 sensors (2 upstream - one off each manifold or downpipe and 1 downstream - after the cat) or 4 sensors (2 upstream - one off each manifold or downpipe and 2 downstream - one before the cat and one after the cat), the upstream sensors are the ONLY ones that deal with the fuel delivery for the engine. The downstreams only monitor the catalytic converter. If you have a bad upstream O2 sensor, it needs to be replaced with another O2 sensor, not a sim as that eBay auction suggests. If replaced with a sim, there will be no adaptive tuning of the engine!

I wouldn't trust anything that doesn't directly plug into the same plug that the original O2 sensor uses. Their statement on "Why pay $50 or more for the "plug and play" type which will corrode in 6 months or less? Save yourself a ton of money and get the same results! Thanks for stopping by!!!" makes me LOL!!! The plug and play units use the same weather packed connectors and circuitry that creates activity in the return signal to the PCM. On new vehicles, the return signal cannot be at a stagnant voltage. If it could be, all you would need to do is to simply solder a properly sized resistor between the voltage supply and the signal return lines and you're done. Basically exactly what this thing is supposed to do.

 

i kinda got a kick out of the 48 hour guarantee
ive used a couple of catcos as replacements. they work fine and dont set off a code. plus the price is right for the universal 2 1/2" in/out cats.