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post #1 of (permalink) Old 09-23-2000, 04:03 PM
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Exhaust restriction?

Howdy, everyone!

I have an '86 Sammy, with 30K miles on it. Recently, it has begun to run REALLY badly after warmup. This symptom will come and go, but it now is mostly here to stay. After W/U (and now, even when cold) this pup acts like spark advance isn't working (it is)... it won't GO. I can hear exhaust escape from somewhere under load (above 2000 rpm or so) like it's leaking past a gasket. Here are the things I noticed:

The catalytic recently started intermittently rattling (but the heat shield seems okay). When the rattle is gone, this problem seems to be worse.

When the symptom appears, the exhaust tube from the EGR (not the vacuum fitting tube) valve blows off the modulator assembly (indicative of very high exhaust pressure?)

Sound like an obstruction to you? In the cat? The odd thing is that this problem can vanish for days or weeks.

I yanked the O2 sensor today and the beast runs well. The modulator hose did NOT blow off.

If you all agree that I should deal with the exhaust, what would you recommend? I live in California, so I need to keep the cat. I'd like to put up a set of headers, a new cat and a reasonably quiet muffler. Suggestions and sources? What kind of cat? What should this cost?



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post #2 of (permalink) Old 09-23-2000, 06:56 PM
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Re: Exhaust restriction?

Check with Petroworks for a Thorley C.A.R.B. certified header, cat and muffler. I just installed the Thorley but used another cat with a Magnaflow Muffler. The Magnaflow is by Car Sound (another California company) and they are straight though design. Quite a bit louder than stock, but I like it.

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post #3 of (permalink) Old 09-23-2000, 07:09 PM
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Re: Exhaust restriction?

Maybe the inside of the converter is broken and obstructing the exhaust. I know a mechanic that was working on a car(escort), it would run fine then all of a sudden it would run terrible. Long story short, it ended up being the muffler. The insides were broken and would block the exhaust sometimes. FWIW Suzuki replaced my converter at 35,000 miles. The Zuk would run about 40 mph. When they changed the converter it ran like a new vehicle. I know a cheap "fix", but it won't work in sunny California, but it could help narrow down your problem.

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post #4 of (permalink) Old 09-23-2000, 07:40 PM
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Re: Exhaust restriction?

If you really only have 30K on the truck Suzuki must by federal law replace your cat con if bad. There is a warrenty
up to I think 50 or maybe 100k. I know 50k anyway. Good luck

Glenn Loud
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post #5 of (permalink) Old 09-23-2000, 08:01 PM
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Re: Exhaust restriction?

If you do decide to go with a Thorely header go direct to Thorley to buy it, quite abit cheaper. They are in Ca., even with shipping to TX. it was cheaper than the Petroworks or RRO.

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post #6 of (permalink) Old 09-25-2000, 11:38 AM
mike shannon
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Re: Exhaust restriction?

replace the cat i have had two of them break free and rattle around.it would do the exact same thing you are talking about.check you egr valve to se if you have blow the plug out of it.i will almost bet money you have. later mike

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post #7 of (permalink) Old 09-25-2000, 12:07 PM
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Re: Exhaust restriction?

Usually the warranty is good for 5 years/50,000 miles on a Cat, at least it was on ours. We had ours replaced at 48,000 miles on the TJ. It blew apart and plugged the muffler, the 200 hp engine had the power of a Yugo. Once it was replaced, it was like a whole different animal. They can check it at stations though, you may want to have it done, no need to even remove it from the Sami.

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