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Should I replace the cat and unercoat?


franc944

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I own a 1990 Reatta convertible 65,000 original miles and I am looking to sell the car for top dollar.

I recently had it up on a lift to get some pictures and it is clean as can be with a little surface rust. Leak free, great brakes and fuel lines etc.

The exhaust sounds great and is totally original. It aint broke but my mechanic says I should change the cat converter to a new stainless one because the one on there is original and "might go in the future" (car passed emissions no problem). He also said he thinks I should undercoat the bottom to make it "look new".

Is he just trying to sell me what I don't need? Will it hurt or help the value of my car?

I think the bottom with stock oem cat and Non-undercoated bottom makes it look like more of an honest car that is original true and clean.

Am I correct in that if I undercoat it and change the cat it looks like I am hiding something?

I know thats what I would think if I saw that on a car I'm buying.

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I own a 1990 Reatta convertible 65,000 original miles and I am looking to sell the car for top dollar.

I recently had it up on a lift to get some pictures and it is clean as can be with a little surface rust. Leak free, great brakes and fuel lines etc.

The exhaust sounds great and is totally original. It aint broke but my mechanic says I should change the cat converter to a new stainless one because the one on there is original and "might go in the future" (car passed emissions no problem). He also said he thinks I should undercoat the bottom to make it "look new".

Is he just trying to sell me what I don't need? Will it hurt or help the value of my car?

I think the bottom with stock oem cat and Non-undercoated bottom makes it look like more of an honest car that is original true and clean.

Am I correct in that if I undercoat it and change the cat it looks like I am hiding something?

I know thats what I would think if I saw that on a car I'm buying.

Two opinions from one person:

1. I think if you had 650 (or maybe 6,500) and not 65,000 miles, then maybe keep the cat original. Otherwise, I don't think it makes a difference in the car's value.

2. Since my 1990 vert with 52,800 miles needed a new muffler but not a new cat, I went ahead and replaced the cat anyway (the added expense wasn't much). The improvement in performance is noticeable (I drove the car for 150 miles between the new muffler and then the new cat). The new cat makes the car go 'vrooom'.

I don't think the sale price of your car will change by replacing the cat if not needed. As for undercoating,...I would clean off the surface rust. Again, you don't have a rotisserie car to sell. You have a Reatta w/ 65,000 miles that has been well taken care of. If you have money to spend on cosmetics, invest in the interior or exterior (first impressions to a new buyer counts!).

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I found it pretty easy to test the cat with the equipment I have.

(1) a 40 year old vacumn gage that will also read pressure up to about 20 psi, probably for testing fuel pumps. I made up some pipe fitting adaptors so I could pull the oxygen sensor and screw in the adaptors, start the engine and have someone blip the throttle while you read the pressure gage, on mine with 44K the pressure never got over 1-2 psi, I expected more but that low pressure indicates there is little back-pressure created by the cat converter.

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In my mind, if it passes smog and you are selling it anyway, I'd leave the cat alone. Wouldn't undercoat it either. Neither add any value to the car.

Prospective buyers typically want to "turn the key", then drive away with everything working and no hassles. So if you want top dollar, fix any obviously broken parts (like inop headlights or worn top), do a reasonable detail job (or have a pro do it), and go from there. Anything less, and you will have to sell at a discount.

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Guest Richard D

I would look for another mechanic. Using his logic you might as well replace the A/C compressor because "it might go in the future"

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I do most work myself. This is a guy who owns a general repair garage in a building I own (my tenant) next door to my office. I told him to put the car up and let me take pics and do a general inspection so I can make sure it's safe and suitable to sell. He couldn't find anything wrong with it and was probably just trying to drum up a ticket.

I would look for another mechanic. Using his logic you might as well replace the A/C compressor because "it might go in the future"
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Personally think undercoating would detract - prospect might wonder what it is hiding. ALso have never replaced a cat but have heard of them disintegrating/rattling.

If do replace cat then for top dollar, get an original and not a universal with the extra tube.

Considering the recommendation for just these two items (not the serpentine belt ?) I wonder if a college payment is due.

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I did the serpentine belt and tensioner pulley when I changed the alternator not long ago. Nice dayco stuff, not the no-name.

I changed the alternator because it was actually bad and not charging the belt was preventive and pulley bearing a little noisy.

If I do the cat I will personally install the Magnaflow direct fit bolt on and will also change the O-2 sensor while I'm there.

Anyone know what gasket I need for bolt on downpipe cat? Is it the foreign car like compression donut style or flat? Should I use band clamp for other end

His rent is 9 days late LMAO!

Personally think undercoating would detract - prospect might wonder what it is hiding. ALso have never replaced a cat but have heard of them disintegrating/rattling.

If do replace cat then for top dollar, get an original and not a universal with the extra tube.

Considering the recommendation for just these two items (not the serpentine belt ?) I wonder if a college payment is due.

Edited by franc944 (see edit history)
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If you want to go the extra mile when working on that end of the exhaust system, remove the restriction in the exhaust header on the firewall side.

I am attaching a photo of a 1991 header but they are all equally restrictive. You need a good metal hole saw or a long burr.

There is between 1/8 and 1/4 inch extra material that can be removed where the header log and down pipe meet.

post-30596-143138796027_thumb.jpg

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