replacing van cats, nothing fancy
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More Turbo
Joined: Jun 2004
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From: Sweden
replacing van cats, nothing fancy
'87 E150 camper van (neat-o inside, a keeper):
Had an exhaust guy tell me he saw the cat was all messed up while he was welding a crack elsewhere. I think he's right, he had it idling on a lift and I could tell the rattle was coming from the second cat. In fact that rattle's had me curious for awhile. The engine's had various problems before which could have burned it with a lean condition, or maybe it just fell apart.
It DID just pass emissions testing last week (I'm as shocked as anyone), but had failed for that crack around the O2 sensor. He said there's still a risk the cat could throw debris into the muffler to clog it and might be a breakdown thing, but I kinda doubt it's possible to clog the muffer like that. But the cat being busted is probably inhibiting the flow and impacting my mpg and power.
The muffler's "new". I don't need anything fancy which might work for a "high performance" application. Not gonna soup up the van unless it's an mpg improvement.
This is an old 2-stage cat system. Physically two cats inline with each other. He did recommend replacing both cats with a new single cat, $350. Which probably isn't bad really, because it'd need new Y-pipes up to the manifolds.
Unless... it is possible to just, I guess, add a new cat after the existing first-cat box the two pipes go into? Maybe knocking out the core of that cat to ensure flow?
Or is there a later model of van at a junkyard that uses a single cat that I could just pull the pipes off of? Maybe reuse old single-cat pipes but buy a new cat?
Had an exhaust guy tell me he saw the cat was all messed up while he was welding a crack elsewhere. I think he's right, he had it idling on a lift and I could tell the rattle was coming from the second cat. In fact that rattle's had me curious for awhile. The engine's had various problems before which could have burned it with a lean condition, or maybe it just fell apart.
It DID just pass emissions testing last week (I'm as shocked as anyone), but had failed for that crack around the O2 sensor. He said there's still a risk the cat could throw debris into the muffler to clog it and might be a breakdown thing, but I kinda doubt it's possible to clog the muffer like that. But the cat being busted is probably inhibiting the flow and impacting my mpg and power.
The muffler's "new". I don't need anything fancy which might work for a "high performance" application. Not gonna soup up the van unless it's an mpg improvement.
This is an old 2-stage cat system. Physically two cats inline with each other. He did recommend replacing both cats with a new single cat, $350. Which probably isn't bad really, because it'd need new Y-pipes up to the manifolds.
Unless... it is possible to just, I guess, add a new cat after the existing first-cat box the two pipes go into? Maybe knocking out the core of that cat to ensure flow?
Or is there a later model of van at a junkyard that uses a single cat that I could just pull the pipes off of? Maybe reuse old single-cat pipes but buy a new cat?
Postmaster
Joined: Oct 2009
Posts: 3,432
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Your system is a three way catalyst with air injection. Basically it works like this. The engine is tuned slightly rich, which creates a low oxygen environment. This minimizes nox output. Then a smog pump injects air into the system after the first converter to create an oxygen rich environment, which allows for an efficient breakdown of hydrocarbons and CO.
You can bring the factory y-pipe together into a single pipe, then run into a standard universal cat that has an air tube in the middle. This approach is fairly inexpensive.
You can bring the factory y-pipe together into a single pipe, then run into a standard universal cat that has an air tube in the middle. This approach is fairly inexpensive.
