Torque Monster and front cats?

[1996explorerxlt]

I recently put on TM headers and now I still have an exhaust leak sound and I checked and its coming from the front cats. I can feel the air coming out of the shields. Is this normal or are my primary cats gone?

I was thinking if they are gone I would do custom down pipes with two high flow cats only. Is this a good idea for performance or do I need more backpressure?

Thanks

 

[MountaineerGreen]

Ideally, you need some back pressure- you may be able to get those cats welded up. They should be able to remove the heat shields, weld up the hole(s) and put the shield back on. I'd explore that avenue before anything else, especially given the high price of converters these days.

 

[CDW6212R]

Universal converters can be had for about $60 each, if the mileage is high at all it may be good to replace them. Do know that if you install shorter or less in number(2 versus 4), the truck will be louder. Good luck,

 

[1996explorerxlt]

160k miles and been in New England salt encrusted winters for 11 years. Im leaning towards having two pipes made with only 2 cats.

Now, two regular cats or two high flow?

I already have 2 1/2" pipes with dual in/out Magnaflow muffler and 3 1/2" tips.(No spare tire)

 

[CDW6212R]

That's the kind of mileage I was hinting at. I bought two high flow 2.5" round cats when I had that mileage, I'll be doing those cat pipes on mine later in Winter. There are only a couple of sizes for universal cats. If you have any worry about emissions testing, you might do better with the kind which look just like stock, with heat shields on them. Catco is the common manufacturer of those. Mine are a little shorter than stock in the brick, no one else has commented on whether they are louder or don't last as long. We'll see,

 

[1996explorerxlt]

After research today I was thinking now I may get these Magnaflow direct fit cats, which I think are high flowing.

http://www.car-sound.com/02product/displaydirectfit01.asp?catalogid=5535&directfit=23311

http://www.car-sound.com/02product/displaydirectfit01.asp?catalogid=5536&directfit=23312

About $320 total.

 

[CDW6212R]

That's a good bolt in replacement choice.

 

[zachow3]

1996explorerxlt,
I just ordered those Magnaflow cats myself today. Couldnt hurt with 162k on the OEM's. I also ordered 2 Thunderbolt Spin cats for my secondary cats from performance-curve.com for $36.95 each. Beats Ford at $500 plus each! Hope these will still not be to loud at idle and normal driving. Right now I have a MAC CAI and 2.5 duel in/2.5 single out with a Flowmaster Delta 40 muffler and it sounds deeper but not obnoctious until you floor it . As my daily driver and so that the wife wont be afraid to drive it I need to keep it fairly quiet. But with my TMH's arriving on the 25th I guess we will see.

 

[CDW6212R]

If anyone needs the rear O2 sensors(Ford), let me know, I might be returning them. I bought all four, and James tells me that I won't need the rear two later. Regards,

 

[zachow3]

CDW,
Do the 02 sensors need to be replaced if I change cats?

 

[CDW6212R]

They aren't linked, they both have a lifespan which is somewhat similar. Some people never change either. The O2 sensors do have much more to do with efficiency than the catalytic converters.

Under ideal conditions they can all go a long time without change. Usually when the engine runs poorly or fuel mileage is low, then the O2 sensors can make an improvement. I've been trying to hold on with my stock parts until I change engines, which will be this Winter. Look at your truck's performance and do a full tune up before doing things like the cats or O2 sensors. Regards,

 

[zachow3]

I dont know what that lifespan is. The reason I am changing the cats is because I am modifying the rest of the exhaust. 11 years for any part in such a harsh enivronment such as exhaust seems very good. The truck ran great from the day I bought it. I dropped $$$ to have my mechanic go thru everything-fluids,tune up,brakes,filters etc less than a week after I bought it since I had no service records. My "goal" is to have a daily driver that is dependable yet I am willing to spend the money to make it more than just a "stock" explorer. Dependable and tame enough so it's streetable( offroading is minimal) but also packs a little more power for towing and and the occasional urge to feel the power from what most people would expect, and I agree, is more like mom's kid carrier than a serious SUV. My approach is to accomplish this with fairly simple bolt on's and not dive into my high mileage motor internals for now. By the way my compression check on all cylinders was between 123 and 130 PSI. That to me seems like a pretty tight motor for 162K. But I work on turbine engines so I'm no expert. CDW, what would you ask for your 02 sensors? If I could get a good deal I certainly would consider them.

 

[CDW6212R]

The O2's which you can buy at stores will be Bosch, some people like them and some don't. I decided on the Ford pieces to be sure, they ran about $75 each for the four, that's my good price. The other kind I think are under $60 each. I would do at least the front if that will be a keeper vehicle, with that mileage. It sounds like I shall not be using these rear O2's when I get it tuned with a flasher anyway. I'd be pleased to ship the rear tow to you for $150. Regards,