If anyone has fears they may be loosing power / economy from clogged or wrong cat...just measure your backpressure and stop guessing at it!

On gas setups: pull a front O2 sensor and screw in a fitting w/ 10' thin vacuum hose and pressure gauge attached. If you see more than 2-3lbs back pressure running, you now know your cat is clogged.

Its worth the peace of mind, I kept my stock 99 cat w/ 150k miles on there!
NC

 

Hello, when I bought my truck it had no cat, just straite pipe. It was a little louder, and my exhaust stunk bad. I ordered a Magna flow Hi Flow cat from O'rielys for $149. Had it welded in. It cleared up the exhaust smell, and I didn't notice any ill effects. I don't know where you was quoted 2k for a cat but I would run and order a Magnaflow 36009 Universal Catalytic Converter - CARB Compliant. And have it welded in, only cost me $40 to have it welded on.

 

Can someone give me an idea of where our cat is in relation to the truck? I think the p.o. took mine off when he had the magna flow exhaust installed. Thanks!

 

No can do here in CA. Must be a CARB approved cat. One can only get one of those from the Ford dealer and when I called and asked, once he started saying 2 thousand......... I didn't hear the other numbers in the price! LOL I did try Carquest but they don't carry a cat for my truck. I also looked online at Napa and as soon as I put what truck I have, they pop back saying they don't have anything for that truck.

Smog guy told me that if I don't have the right CARB approved cat, and get caught, they could fine me, or have my truck towed and mark it as automatic fail for smog, even if I passed it. I'm really not that worried about things like that, but figured I would still save for the right one and not have any problems at all!

 

According to this cat on Amazon.com It states it is CARB Compliant. And Meets california code.

Amazon.com: Magnaflow 36009 Universal Catalytic Converter - CARB Compliant: Automotive

It is also available from summit racing: MagnaFlow 36009 - MagnaFlow California 30000 Catalytic Converters - Overview - SummitRacing.com

 

When I put the make "xlt" and the size engine 6.8 v10 it say's it does not fit my vehicle! Hopefully this link works on what all it says!

Amazon.com: Magnaflow 36009 Universal Catalytic Converter - CARB Compliant: Automotive Nope link didn't work. If you put in xlt in the "select trim" spot, then put 6.8 v10 in the engine spot, it will open another page saying it doesn't fit that truck.

I just selected all engine types they have and all come back as saying it will not fit my vehicle.

This is the cat I have on it now, it almost looks like the same one as in the link!



Here is what it say's on the bottom. Someone here said it is not the right one for the size engine I have!

 

When I go to Amazon I go to Automotive, I put in year, make, model. then click on Catalytic Converters under exhaust, then put in XLT, then 6.8L V10. It still lists the 36009 for CARB Compliant.

 

The OP has a V10, like mine. I gave diesels as an example of things that have been designed to work with. Just because something's been designed to work with an engine, doesn't mean it has no impact on that engine's performance.

I realize the emissions standards are different for trucks and smaller vehicles, but you claim the newer cats don't do much to hurt performance; and I gave you example of cats on a newer and older vehicle that do impact performance quite a bit. Not to mention, over years they can get clogged, break the honeycomb inside and rattle like there's no tomorrow, etc. One more expensive worthless part. If you don't want to spend the 400-1000 bucks I've been seeing for a new factory cat, and you can get away without one, do it.

The original question was whether there was will be a check engine light if they take the cat off. That will be decided solely upon whether the truck was a CA truck originally, and has an O2 sensor after the cat or not.

OP: Autozone comes up with some 400 dollar Maremont replacements for me, and they don't seem the kind stocked, they'd have to order them, so they should be available at all autozones.

CA emissions laws are downright idiotic. And they wonder why they're broke... /rant.

 

That is a universal cat converter. If the current truck pass emissions with the current cat and the cat is not glowing orange (heat from being clogged) or causing excessive backpressure in your system I would not worry about it.

Nobody has been able to tell me if the the GVWR and engine displacement ratings are based on flow or if the rating comes completely from emissions output. From what I am reading and seeing it is the later. The stock converters do not flow well however are very good at reducing emissions output. A converter designed for a high performance application is usually the opposite. The OE has certain emissions guidelines which the truck has to meet.

I have a little dynatech offroad cat on my V10 to pass the visual and it has worked great for the past 30k+ miles. My dad has a cat on his V10 about the size of the converter in the pic above for around 70k miles. However keep in mind neither my V10 nor my dads has an O2 sensor after the converter. I believe the SD gassers destined for smog states do have post cat O2s though.

 

Ok, went and checked. I do have the post cat sensor. So I guess it doesn't matter if I take the cat off or not. Unless, what if I just disconnect the sensor, or cut the wire going to it? I just hate that irritating light!

If this cat that I have now is indeed a universal one. I would hate to go buy another universal one and have the same problem. I tried to get hubby to go for having a friend in Arizona get us a cat for the truck, but he wants to wait for now. Say's we don't even know if we will have the truck by the time the next smog rolls around. UH, yah we will! LOL

 

If you have the post cat sensor, it will detect there's no cat or a less efficient cat there - that's its job, to measure the catalyst efficiency, and it will throw off a check engine light. You can have the rear sensors turned off in a tune I believe, at least i was able to on my mustang. My rear o2 sensors on that are zip tied to the transmission

You won't pass california emissions/inspections without a cat though, and you may get in trouble out there. Cheapest solution would be to move out of that state.

 

Almost positive that won't work. The computer sends a signal to the sensor and waits for a reply, if it doesn't get one or it comes back out of spec then it triggers the light. I think you have to trick the computer into thinking there's still a cat there and that it's reading normally. I have no clue how you do it, but I've heard of it being done. Do a search on here, surely something will come up.

 

To trick it the old school way, without a tune, a MIL (Malfunction Indicator Light) eliminator would be needed; it's basically a resistor in a small extension for the 02 sensor. I've used one before, but for the price, might as well get a tune for the truck and call it a day; much better for it.

OP, you can google MIL eliminator and should be able to find instructions on how to make one cheap or where to buy one already made...

 

If your getting the vehicle inspected and smogged in CA your going to need that post cat O2 and have a cat converter on the truck which allows you to pass smog. The O2 can be be turned off with a tuner however that will not help your current situation at all. Tricking the pcm with resistors is one of the dumbest things you can do.

 

i have the same cat on my 04 F-350 with 5.4 and its too small. when i tow my backhow or beat on the truck in the summer you can hear smell the cat real bad. this is what i found thats going to flow good and it can handle the truck
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