1985 Catalytic Converter opinions?

[ChuckG]

I have a "cleaned out" OE cat on the car now, and though it sounds tough, the car just isn't running right. I hollowed it out because the core plugged up solid.

I've come to the conclusion that I need a proper cat. I only drive the car about 2,000 miles a year, but I'd like to have it run better.

I know, if I can even find one, an AC-Delco converter will break the bank. Nobody seems to stock them anyway.

I've found Walker, Catco, and Magnaflow at Ecker's, et al. All are reasonable, but which one?

Any thoughts out there?

[aquaholic]

does an 85 even have an o2 sensor? thats what would make it run bad when you hollow out the cat. if it doesn't have one (which i dont suspect it does) i'de say the running bad is just a coincidence. hollowing out the cat on something that old shouldn't make a dam lick of difference in the way the car runs. you had to have done something else chuck.

[ChuckG]

Yep, it has an O2 sensor, on the squirrely 2 into 1 into 2 exhaust, just upwind of the converter on the driver's side.

Your thought is the lack of the cats guts is making the O2 sensor send bad info?

I am running rich.

Arrgg! $200 on something I can't see or polish and won't make me go faster?!? That's just wrong!

Maybe it will quiet the beast some. I could use that. Impossible to make conversation when driving.

[bradfordsvettes]

I doubt that a hollowed out cat would make it run bad it may lean it out some but the O2 should make up the difference. you would really need to put a scan tool on it and drive it .These and other early cars had injector problems and could be starting to rear its ugly head .The cat is mainly so your grand kids can have clean air and no horns growing out of their heads from what I have been told at schools Steve

[aquaholic]

if that o2 sensor is before the cat where you are describing then i still stand by my statement. hollowing out the cat did nothing. it would only have an effect if the car had o2's after the cat as well. there's something your missing. either that or coincidently, your pre cat o2 sensor is just biting the dust. no shame on it since it's 25 years old. your o2 sensor needing replaced would make the car run rich and make it run bad as well. it will eventually wear out to the point where it sets the check engine light. i believe those sensors have a life of around 10 years or 60,000 miles.

[ChuckG]

The O2 sensor was replaced about six years and 13k miles ago. Pretty sure it's gotten hot a few times. Think it may have been there when I cooked the first engine. They're not expensive, so I'll replace it.

I ordered a new cat from Eckler's anyway. Even if it just quiets things down, it's worthwhile.

I did replace the fuel pump, so it is running better. Even starting when hot. Still, I need to test the injectors. they've been serviced, but never properly checked.

[bradfordsvettes]

Originally Posted by aquaholic

if that o2 sensor is before the cat where you are describing then i still stand by my statement. hollowing out the cat did nothing. it would only have an effect if the car had o2's after the cat as well. there's something your missing. either that or coincidently, your pre cat o2 sensor is just biting the dust. no shame on it since it's 25 years old. your o2 sensor needing replaced would make the car run rich and make it run bad as well. it will eventually wear out to the point where it sets the check engine light. i believe those sensors have a life of around 10 years or 60,000 miles.

You are correct in your statement I was not saying you were wrong only that the O2 is there to make adjustments to fine tune the system and a lazy O2 can give you concerns as well as shorted injectors.As for the rest of your statement the post cat O2 has nothing to to with the running of the engine it is there just to monitor the cat and how efficient It is operating it will set a light if the cat is not doing its job only,barring wiring or heater problems hope this helps both of you Steve

[ChuckG]

I've recently heard no cat reduces back pressure, therefore heat, to the O2 sensor and since I'm using a "stock" parameter O2 sensor, it's not sending valid data back and the ECM isn't set up to make the necessary adjustments.

Make sense?

[c4c5specialist]

HI there,
Walker/Eastern is the best I have seen personally.
I know they are still available and the 1985 GM system has been discontinued.

Here is one link.

Catalytic Converter - Direct Fit - OEM Quality at Discount Price

Alllthebest, c4c5

[ChuckG]

Thanks Paul! That's $40 cheaper than anyplace else too!

How goes the job search? I wish there was more we could do. Hopefully, any prospective employer will check here and see how amazing your volume of knowledge is.