I have a question for you guys.. what would you say if I told you my CAT. is blown out the truck smells like an old Chevy.. the Cat is not doing what its supposed to do and you can hear rattling inside like the sound of how a thin heat shield rattles when its loose up against another piece of metal, but the kicker is.. it does not trigger a code.

Am I wrong on 97 shouldn't the O2 sensor cause a code or check engine light?
Would it not being it would be reading unburnt fuel cause the motor to lean out the mix?

SO I already know my Cat is bad, I'm replacing the POS Magna-Crap with my Stock one.. but it leaves the question.. why is it not triggering a code, could a bad 02 sensor?

When i swapped out the CAT, and swapped the 02 sensor it looked faily clean.. it was typical **** on it but not like caked up..

I have no clue if its been replaced or not.. the exhaust system that was on it looked factory.. and I currently have 133K on the truck..

Is this something i should have looked into further before replacing the CAT?

 

And what do you think about DENSO 02 sensors? What about DENSO as a company are they any good?

 

I say start with a new cat see what happens dont spend $$ for a new o2 unless you have the $$$ then just do it but keep the old O2 it may be fine or may run better with the old o2.

I do think it should be giving you a code but maybe just having a old cat will not activate the o2 and send a code.

A new cat will probably clean out the o2 for you.

I say if it runs fine forget about it

 

I have the same problem, bad cat and ratteling around and no engine code. Computer must have leaned out the mix so it wont throw the code.

 

Doesn't smell lean.. :P lol

 

get a spintech cat, best exhaust mod that I have done thus far.

 

I've heard they are mostly all manufactured by the same company.. just different stamps on them.. ??? IDK...

 

the spintech cat is made by catco. you cant go wrong with it. its been proven to be better than that restrictive as hell stock cats. i was skeptical about the cat but bought it to test it out. never looked back. i used to have a dead spot in the rpm band and after it was gone.

 

The ceramic plates look sexy.. the magnaflow has little triangles. Stock has circles.

magnaflow has addmitted that the O2 sensor on their product is in the wrong location. They are checking what should be done. I'm going to request that they refund my money; no matter if its through Summit or not.

 

That cat sounds great I want one of those cats I’m not sure what they installed on my truck with my new quality stainless steel muffler I think it’s just a cheap fit all cat unit.

I have learned so much on this great forum