Multiple Cats For Inline Six

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Nov 25, 1999 | 12:10 AM

David C

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Multiple Cats For Inline Six

Just read the messages concerning catalytic converters for inline sixes. Left me with one question, how many cats are suppose to be on my truck? '87, inline six, 1/2 ton, two wheel drive with manual transmission. Thanks

Nov 25, 1999 | 08:50 AM

Fast Eddie

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Multiple Cats For Inline Six

The catalytic setup that was on my '91 4.9L 5spd. looked like this: Two cast iron exhaust manifolds bolted to the cylinder head; each manifold emptied into a (if I remember rightly) a 2.25-inch diameter length of header-like tubing which dropped down into the vicinity of the starter, where both of these tubes dumped into a "flattened can" about six inches long; a 3-inch tube exited the rear of this can, made its way over a crossmember, and into what I am sure was a catalytic convertor.
The "flattened can" has always puzzled me; I assumed it was a pre-convertor or something. Recently I've read "resonator", and like you, I'm wondering, too; especially so since the whole assembly, manifolds-to-rear-of-cat, mysteriously fell off the truck some years ago and was unfortunately found to be beyond repair after suffering multiple blows with what appeared to have been a large heavy object, perhaps a sledge hammer, rendering said flattened can unidentifiable (and beyond repair, per Texas and EPAs' smog law definitions of when to replace). Imagine that. A most heinous crime. I was forced to replace all of above with headers and a high-flow cat. Poor me. Poor EPA. Poor pre-cat.
Lucky truck, it loves the present setup.
Ed

Dec 3, 1999 | 12:54 PM

PAUL_2

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Multiple Cats For Inline Six

As Fast Eddie described , as far as I know up to the 97 models , the 4.9 's used two cats

Dec 3, 1999 | 01:32 PM

slik

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From: saramento usa

Multiple Cats For Inline Six

My '82 300 I6 with carb had only one cat with no resonator: Manifold to cat to exhaust to tail

Slik

Dec 3, 1999 | 02:22 PM

Alex Stephan

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Multiple Cats For Inline Six

My '95 F150 has dual cats, with 2" I.D. exhaust. I want to get a better breathing exhaust system. Does anyone know of a larger diameter cats or F150 exhuast system I could get from a junkyard rather than new?

Dec 4, 1999 | 02:03 PM

Rick

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Multiple Cats For Inline Six

The two cat's on your 4.9 liter are for California
emissions law..,California has the strickest
emissions law in the U.S.A. so auto manufacturers comply by these emission laws. In reality, your
4.9 liter will still pass emissions inspection
with one cat.
EBTE tech