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Discussion Starter #21
crumbling when touched the rust is probably surface rust only.
You do have two rubber lines coming off of the tank that you did not mention you replaced.
Like i said, flaky as baklava.. Should likely replace them.. No smell/leaks though. As far as the rubber lines from the tank I will put that on the list..


You can also cut the old cat out of the pipe and install a Universal Cat
Would you consider this more as a "temporary fix"? Or is it a fair supplement for the magnaflow swap.
Is there a specific Universal Cat that I should purchase (size, length, capacity, membrane...etc)


The OP can test back-pressure himself instead of paying someone.
But if I swap out the known defunct cat.. I shouldn't have to run this test, right? Maybe, after the cat swap, I'll test it for assurance reasons...


Im going to run a compression test just so I can get that information into the thread in case it is necessary for speculation purposes -- ill be referring to my haynes manual while doing so.
 

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Installing a Universal Cat is perfectly fine and Legal, permanent repair as long as you have a Cat approved for the state you live in.

California, New York and Maine have more stringent emission standards and Cats are made just for those states, all other states are Federal.

I installed a universal cat on my car and that is usually what exhaust shops install except they weld it in rather than using clamps.

RUNNING A COMPRESSION TEST
SPECS-Engine Compression.jpg
 

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Discussion Starter #23 (Edited)
Ran compression test.

I took videos so feel free to review if you like:

Dry Comp Test (1-2-3-4) :
[ame]https://vimeo.com/369946034[/ame]

.

Wet Comp Test (1-2-3-4) :
[ame]https://vimeo.com/369945834[/ame]

Results are as follows:

Dry test
Cylinder#1 = ~110 psi
Cylinder#2 = ~95 psi
Cylinder#3 = 120 psi
Cylinder#4 = 120 psi
------------------------------
Wet test
Cylinder#1 = ~110 psi
Cylinder#2 = ~90 psi
Cylinder#3 = 120 psi
Cylinder#4 = 120 psi

Now i realized after I ran this test that my engine was not at operating temperature. Not sure how much of an influential factor that is but I thought I would mention it.

It seems like Cylinder#2 is low in compression. 😞

Does this indicate a bad exhaust valve?

I'm going to do a cat swap today if the weather permits.
 

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Administrator
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Ran compression test.

I took videos so feel free to review if you like:

Dry Comp Test (1-2-3-4) :
https://vimeo.com/369946034

.

Wet Comp Test (1-2-3-4) :
https://vimeo.com/369945834

Results are as follows:

Dry test
Cylinder#1 = ~110 psi
Cylinder#2 = ~95 psi
Cylinder#3 = 120 psi
Cylinder#4 = 120 psi
------------------------------
Wet test
Cylinder#1 = ~110 psi
Cylinder#2 = ~90 psi
Cylinder#3 = 120 psi
Cylinder#4 = 120 psi

Now i realized after I ran this test that my engine was not at operating temperature. Not sure how much of an influential factor that is but I thought I would mention it.

It seems like Cylinder#2 is low in compression. 😞

Does this indicate a bad exhaust valve?

I'm going to do a cat swap today if the weather permits.
Swap your cat and go from there as far as your lack of power issue is concerned.

1)The 10 PSI below minimum is not causing your current issue.
2)If you really want to know where the compression loss is you now have to run a Cylinder Leak Down Test.
a) A compression test shows the engines ability to build pressure, a cylinder leak down test shows the engines ability to hold pressure and where the loss of compression is coming from.
Without running a leakdown test you can only make an uneducated guess where the compression loss is happening.
b) You need a cylinder leakdown tester and an air compressor that can produce and hold a minimum of 100 PSI.
c)Remove all spark plugs.
d)Bring #1 cylinder to TDC on a compression stroke
e)Install the hose from the leakdown tester into #1 cylinder and connect to the leakdown tester.
f)Hold the throttle plate wide open, remove the radiator cap and the oil filler cap.
g)Connect your shop air to the leakdown tester and slowly open the air valve until the shop air gauge reads 100 PSI.
(You may need a helper to use a breaker bar and socket to hold the crankshaft still, the piston will want to travel to the bottom of its stroke when the air pressure is applied)
h)Read the pressure on the other gauge, that is the PSI the engine is holding in that cylinder.
i) Turn the crankshaft 90 degrees clockwise (which will bring #3 cylinder to TDC) and perform the leakdown test on the next cylinder by firing order.
Firing Order 1, 3, 4, 2 Clockwise
j)Repeat until all 4 cylinders are done.

READING YOUR RESULTS
1)Naturally you want to be as close to holding 100% in each cylinder (100 PSI) as possible
The max loss allowed on each cylinder would be 25% for rings, 10% for intake/exhaust valves, 0% for loss into the cooling system.
2) To know where the loss is coming from you need to use your eyes and ears.
a)When you are testing each cylinder listen at the throttle body, oil cap opening and exhaust pipe, and look at the coolant in the radiator.
What Each Means, Air Heard From The...
1)Throttle Body indicates a leak from the intake valve
2)Exhaust indicates a leak from the exhaust valve
3)Oil Filler Capopening indicates leakage past the rings
(Some loss past the rings is normal, you are allowed up to a 25% loss)
4)Bubbles in the coolant indicate a headgasket issue (in worse case scenarios it could also mean a cracked head or block)

CYLINDER LEAKDOWN TESTER
This is the one I own.
https://www.tooltopia.com/otc-tools-5609.aspx

HOW TO
https://mobiloil.com/en/article/car-maintenance/car-maintenance-archive/how-to-do-a-leakdown-test


 

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Discussion Starter #25
I was going to swap in a universal cat today -- but the cat was too small and I wasn't about to self induce a headache trying to add sections and clamps to make it work... I also noticed the cat that was given to me (as well as other options provided from other parts stores) was missing the tie-in point that I believe recirculates the exhaust... I will attach a photo of what I am talking about.

If it is absolutely necessary that I get a cat with this connector in the middle then I have to know for sure that the direct fit Magnaflow (#23252) will have this connector? The photo they provide is just a 3D render.


Connector in question:
IMG_20191031_122025.jpg
 

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The connector in the center is for the aspirator valve if needed. It adds air into the converter between the beds. My 1986 2.2L TBI convertible (originally) had that exact system.
 

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Discussion Starter #27
The connector in the center is for the aspirator valve if needed. It adds air into the converter between the beds. My 1986 2.2L TBI convertible (originally) had that exact system.
So if the new cat does not have that connector on it is it fine for me to disconnect / remove the aspirator valve and have it not connect to anything?
 

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The air pump/aspirator system flows air into the Co/HC portion of the cat since O2 is needed for the Catalyst to work. Since you do not have emissions testing it is your choice weather to leave the aspirator tube disconnected from the Cat. If you do save the pieces. You can measure the length of your Cat, get the inlet and outlet pipe diameter and go to the Walker Exhaust website and it will lead you to a universal Cat with those specs. I will be away until Monday if you have any issues.
 

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Discussion Starter #29
VICTORY!! So to touch bases on the situation. I replaced the cat with the direct fit part above and that did it. the membrane was broken into a few pieces. it's possible some traveled into the resonator but I didn't actually check unfortunately it didn't cross my mind to do so when I was installing the new section.

Runs like a dream now. going to be putting it up in storage shortly now that the snow has began to fall.

I had to remove the aspirator because the cat didn't have a connector for it. I kept the part but completely removed it and capped the portion that connected to the manifold/engine . I was told this should be okay and won't affect performance

The next thing I'll look into doing is that leakdown test
 
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