My Engine Light is on, so I took my car to Autozone and had them plug in the tester. It said that the Catalytic Converter needs to be replaced, so I took it to a local muffler shop to get looked at. They put it up on the lift and found that my car (96 Camaro SS) has two catalytic converters on it, one real close to the engine, another a little further back. They said I'd have to take it somewhere and have diagnostics done to find out which one isn't working properly. Does anyone know if one or the other tends to fail more often? And should I go with a high-flow catalytic converter to replace the old one? What sort of price difference am I looking at. The place I went to quoted $180 to change out the one by the engine, $90 to do the one further back (it looked smaller, and was considerably easier to get at). Sorry, I'm a total newbie to this kind of stuff, any help offered would be most appreciated.

 

i dunno about finding out if its the front or rear cat but i would deff replace with a highflow maybe not for performance but i think they should be cheeper then a new gm cat (could be wrong here)

 

call tsp, spoke with john and he can get them. he didnt have a price right away as he was walking out the door, but i think ive seen the random tech. for $90ish a piece. any exhaust shop should be able to throw them on cheap.

 

The code tells you which side is bad.

 

I'll try heading back to Autozone in the morning and see if the code will tell me which one is bad. Sounds like the high-flow cat is the way to go. Anyone else have any helpful advice?

 

It would appear they got the code for low cat convertor efficiency. That could indicate a problem with the cat, of with the after-cat O2 sensor. The code told them whether it was the cat on the left side (Bank 1) or on the right side (Bank 2).

Although the convertors are shaped differently, and located differently, they are not in series (one "front", one "back"). Each cat serves only one bank of the engine, and their function is identical. Either one can die with equal probability. Again, when AutoZone read the code, it told them which side of the engine was having the problem.

First determine if it is a cat problem or an O2 sensor problem. Swap the left and right side after-cat O2 sensors from side to side. If the problem stays where it was, its a faulty cat. If the problem switches sides with the O2 sensor, its a sensor problem.

If you are going to go with high flow cats, it would make sense to replace both of them, to keep the banks of the engine balanced. You can get a complete dual-cat Y-pipe with high flow cats, and larger mandrel-bent tubing. Unless you are considering headers in the future, that would be the way to go, and its something you could probably change out yourself to save $$$$.

 

Thanks everyone for the info. It is definetly one (or maybe even both) of the cats. I think the high flow cats sound like the way to go, but I live in Illinois where there's emissions testing. Will my car pass emissions with high flow cats? And I really liked the sound of the set up Injuneer recommended, where can I order one, and what do I call it? A "Dual Cat Y Pipe"? Or do I need to order several pieces? Thanks for the help guys, I appreciate it.

 

Two of our supporting vendors, Tbyrne and Thunder Racing, sells the Random Tech dual cat y-pipe for the 96/97 LT1s. I should know...I'm installing mine on Wednesday.

It's "one" part number, but it's actually 2 pieces. The bigger piece that has the 2 RT cats installed mounts to your passenger side. The small piece connects the bigger piece to the driver side. My order actually came with an O2 extension,which you need for the driver side, since it's moved from right after the exhaust manifolds to right next to the drivers side.

Now will it pass smog..I sure hope so. Technically, the RT y-pipe moves the cats, so not legal. What I hear is that it will pass the sniffer with flying colors...visual..depends on who's inspecting it. I live in California where smog checking is a scam...I mean business....some places do visual checks. Some don't know the difference b/w aftermarket cats or not, as long as they see 2 of them.

To be safe, I'm keeping my stock y-pipe in case I need to pass visual. You might not have an option if your cats are bad.

But if you have a high mileage on those O2 sensors...you might think about replacing those as well since you're already in the area. Go to GMPartsDirect to order them cheaper than what I paid at my local parts store. I had 85K miles on them before I changed all 4 out...made a big difference on how the car drove.

 

cut them out and get a computer tune to delete the rear o2s..your check engine light wont be on anymore for that and you wont have to deal with cats anymore...thats the way i went

 

Perhaps I am reading this wrong, but I'm looking at the Tbynre site and it looks like each high flow cat is $199, or if I want the Random Tech Y-Pipe with the dual catalytic converters it is $535 just for the part . After adding install that is a BIG jump up from the $270 quote I received at my friendly local muffler shop to put in regular cats. Are high flow cats worth an extra $400? That's a good chunk of change that could be put towards more important things, like car payments, house payments, headers , etc. Someone please correct me if I'm wrong (I'm hoping I'm wrong).

 

what is your milage on your car im going through the same thing in my car i have no SES light on but they are starting to stink like rotton eggs. so long story short im going to bitch to gm about the proublem and have them good-will the proublem since all cars come with a 7 or 8 year warrenty or 80,000 miles im over by 3,000 miles.

Here is a short story a customer had to have the whole dash removed to change the evapratory for the a/c system. the truck was a 03 with 60,000 miles like 30k out of factory warrenty. the customer called gm and bitched and they covered he proublem as normal warrntey go figure.

 

My car has about 66000 miles on it. It's a 96, no way chevy is going to help me out, that's not even an option.


Anyone have any experience with the Random Tech Y-Pipe with dual converters? Is it really that damn expensive? Is it worth the money? Help!

 

Hi, New to the boards. I got a 2000 Camaro SS and I just took it to Autozone for the SES. Code is P0420 - Catalyst System Efficiency Below Threshold (Bank 1).

I only have 15,000 miles on the car. I bought an extended warranty (2 extra years making a total of 5) but my warranty ran out in April

The only thing I did was have the muffler shop put a Flowmaster muffler on just for sound (didnt need it), but that was over a month ago and then SES just came on now. Are the two related? My muffler shop says no.

What should I do, just reset it ?

I am in Michigan.

Thanks in advance for any help !

 

buzzsaw:

First... check your factory warranty. The emissions stuff should be covered for much longer than the rest of the car. Your cats are probably still covered with that low mileage.

Your code could come from a faulty cat or a faulty sensor. Swap the after-cat O2 sensors from side to side. If the problem moves to Bank 2, its a faulty sensor. If the problem stays on Bank 1, its a faulty cat or a sensor wiring problem.

It's not related to the muffler install.

 

I went to Autozone and reset the code. It has not come back on today with about 10 miles of use.

I keep my fingers crossed.

Thanks for the help !