Single catalytic converter (1 Viewer)

[Bigdrewbowski]

I was getting a catalytic converter CEL code on my 1997 LX450. I did some online shopping and decided to go with the Magnaflow 99006HM universal ones. Since Magnaflow stated this was for front or back, I ordered two to go inline.
I got a call from my muffler guy telling me that there was not room for both of these between the O2 sensors. He suggested just putting the one in. He said he was sure that would be enough to not throw a code. Well, it has been 5 days and no code yet. I am only posting because I have seen others that insist you have to run 2 catalytic converters. If The Pig throws a code I will update this post, but so far so good.

 

[inkpot]

I am running a single short 3-way cat on my 97 for several years. No problems and it passes smog in Az. It is short enuff to make
it easy to run exhaust over frame like 93-94.

 

[plutonius]

I ran a single Magnaflow for a while as well, no codes and passed smog with it here in California. The cat did not last me more than 2 years, although that could be due to the conditions of my own rig. YMMV but I hope it works well for a good long run!

 

[JHB Cruising]

Here is what I did. Better clearance and I like how it sounds. Got to be worth 20mpg and 100hp

 

[Mandrake]

The letter of the law states that if it came with two cats, it needs to have two cats in order to conform to federally mandated emissions requirements.

But I personally see nothing wrong with having one if it won't be an issue come inspection time.

 

[jonheld]

I did the Magnaflow downpipes with the single horizontal cat a few years ago. No issues with passing smog along with a visual inspection in NJ.

 

[inkpot]

The letter of the law states that if it came with two cats, it needs to have two cats in order to conform to federally mandated emissions requirements.

But I personally see nothing wrong with having one if it won't be an issue come inspection time.

Inspection/ monitoring/ enforcement are all left up to the individual states, and those state programs are ALL OVER the map! Some states may have requirements above and beyond the federal specs. Other states have NO monitoring program at all!! Reportedly, California is the most strict. Arizona has Collector/Antique status for older cars that waived smog requirements, but it does saddle the owner with limiting constraints on whennand how far you drive. Oddly enough, the mileage monitoring is legally assigned to the owner’s insurance agent, duh?!?’

 

[Bambusiero]

Actually, the letter of the law on catalytic converters - Well, nevermind. It'll just piss you off.
Basically - You can't touch that! And if you do, put it back the way it was. And sign and date a sworn statement justifying why you did it.
Fortunately, everyone just ignores all that around here.

 

[Tools R Us]

The letter of the law states that if it came with two cats, it needs to have two cats in order to conform to federally mandated emissions requirements.

But I personally see nothing wrong with having one if it won't be an issue come inspection time.

It depends on who, what agency is interpreting the regulation? I had a talk with an emissions waver tech, who pulled out the big book and looked up my rig, '96 LX450. It says, 3way cat system, one 1way and one 2way cats, if replacement is needed a properly sized, displacement and vehicle weight, 3way cat is acceptable. Asked about the two cat thing, his reply, that is how it was done, tech has advanced, so now one cat can do the job, two would be redundant, unnecessary. That is how Arizona interprets it.

 

[Mandrake]

I'm sure that one newish cat is better than two 20+ year old cats, and if I were an inspection station, I wouldn't look twice if there were only one. I agree tech advances, but there are caveats...

Paragraph 8, section 6 and section 9... then read paragraph 11:

Federal EPA Aftermarket Catalytic Converter Fact Sheet

Don't take this as me saying the OP needs two cats... when it's time for me to deal with it, I'll be going with one cat. I only brought it up for the sake of furthering knowledge and the discussion and to maybe help someone avoid a failed visual on the off chance the ref knows his business. I mean... there's people out there that think because their county doesn't do emissions, they don't even need a cat...

 

[concretejungle]

i'm running a single cat system just like what is pictured above... however, i had to get a rear O2 sensor immolator so i wouldn't throw codes. without it, my rig would toss insufficient cat CEL

 

[Tools R Us]

I'm sure that one newish cat is better than two 20+ year old cats, and if I were an inspection station, I wouldn't look twice if there were only one. I agree tech advances, but there are caveats...

Paragraph 8, section 6 and section 9... then read paragraph 11:

Federal EPA Aftermarket Catalytic Converter Fact Sheet

Don't take this as me saying the OP needs two cats... when it's time for me to deal with it, I'll be going with one cat. I only brought it up for the sake of furthering knowledge and the discussion and to maybe help someone avoid a failed visual on the off chance the ref knows his business. I mean... there's people out there that think because their county doesn't do emissions, they don't even need a cat...

Agree, will very by state, county, etc. Here the '96 and newer get a test break, they only plug into OBD2 port, briefly run the motor and check the fuel cap, and every other year. the '95 and older gets the pipe sniff, visual inspection, cap and every year. So on the '96 and newer, as long as the ECU is happy, from a test perspective, doesn't matter what equipment, they don't look.

 

[ScottyDog]

View attachment 1685699 Here is what I did. Better clearance and I like how it sounds. Got to be worth 20mpg and 100hp

Who did you're exhaust? I need to do something with mine.. cat is rattling like a tin can, I had to cut the resonator off, cuz I smashed it and my stock 20 year old muffler needs new bearings.. LOL
ScottyDog

 

[JHB Cruising]

Mesa Muffler! They kept it high and tight.

Who did you're exhaust? I need to do something with mine.. cat is rattling like a tin can, I had to cut the resonator off, cuz I smashed it and my stock 20 year old muffler needs new bearings.. LOL
ScottyDog

 

[ScottyDog]

Mesa Muffler! They kept it high and tight.

Awesome! Thanks for info!