Catalytic Converter question

[ws6drbob]

My Passenger side cat is rattling so its prolly on the way out so I was wondering what my options were as far as fixing it. Since its a two cat system if I have a muffler shop weld in a straight pipe and put in some o2 sims would that have any negative effects on the car? Or should I just replace cat? I just figure it would be cheaper to go the first route.

[Joe 1320]

Muffler shops are bound by strict laws concerning emissions systems. 99% won't put a pipe in place of a cat, they can lose their license and have to pay heavy fines. They are realy touchy about that. Just replace the cat and you'll save yourself lots of aggrivation.

[94 formula]

My Passenger side cat is rattling so its prolly on the way out so I was wondering what my options were as far as fixing it. Since its a two cat system if I have a muffler shop weld in a straight pipe and put in some o2 sims would that have any negative effects on the car? Or should I just replace cat? I just figure it would be cheaper to go the first route.

Is it the cat rattling on the inside or is a mount bad and is the exhuast hitting somewhere? With a dual cat system I'd never just get rid of one and let the other there. Like Joe said many will not just cut it out for you, but if you know someone that works in a shop or go by and talk to some of them they can be very helpful . Many shops won't cut out a cat but have no problem welding a pipe into an open area if you'd happen to cut them out yourself and are looking to save a little money.

[Injuneer]

If you eliminate the cats on your 1997, you will need to replace the two after-cat O2 sensors with O2 "sims" to convince the PCM that the cats are still there. Otherwise, you will be looking at an SES light and some codes. Alternatively, the diagnostic for the after-cat sensors can be programmed out of the PCM, but that will leave you with a "System not ready" flag if they hook up to your ALDL connector for an emissions check. Some juridstictions allow one or two "not readiy" flags.

And you do realize that your "two cat system" consisits of one cat for each bank of the engine, and that by eliminating only one of them, your are causing an imbalance between the two banks?