What have you done to your square lately??

[JamesSam]

You won't gain much, possibly not even enough to feel. Unless of course it is badly plugged, which might actually be your entire problem.
It will sound different...better or worse depends on your opinion.
Since yours is TBI with the smog(air) pump you may get some other issues...you may not.

If it were my truck and that was in the way of one side I would probably start with the other side to see if that fixes or helps. It looks awful on the outside...I would probably be thinking about an aftermarket, free flowing option.

I understand that folks just love stealing them to the point of shooting and killing to get them.

Ok I am now guessing the TBI would have trouble with no catalytic converter being in there?
I was actually getting somewhat excited to have a solution to this so easily...but I have not thought about the complications of a TBI set up versus a just carbeurated set up. I imagine the straight pipe solution would be no problem on a carbeurated set up-pre 1987...

 

[legopnuematic]

If I’m not mistaken these trucks with tbi should be just an upstream O2 sensor, no downstream (after cat). What is after the sensor is of minimal impact to its function (please correct if this is wrong).

Has it been determined if the cat is visually in the way or actually in the way? If there is an inch of clearance between the bolt head and the cat or more, you should be able to work around it. Might have to fly blind, and not as convenient, but should be doable.

 

[JamesSam]

If I’m not mistaken these trucks with tbi should be just an upstream O2 sensor, no downstream (after cat). What is after the sensor is of minimal impact to its function (please correct if this is wrong).

Has it been determined if the cat is visually in the way or actually in the way? If there is an inch of clearance between the bolt head and the cat or more, you should be able to work around it. Might have to fly blind, and not as convenient, but should be doable.

It seems damn near impossible to access all 4 bolts on this drivers side tank bracket with this gigantic oval cat where it is. Also, I understand that if the cat is clogged it could be the, or one of, the reasons for the symptoms of the engine studdering. I am trying to kill two birds with one stone, being able to trouble shoot the passenger tank that I am currently using, and save labor expenses by doing it myself. Not sure if it's all worth it honestly but, I'm doing it...what do I do now? Dang.

 

[JamesSam]

It appears the catalytic converter is not required on a vehicle as old as mine, or any of ours, here in VA.
If deleting the cat won't mess with the driveability of the truck it is the cheapest option. (It seems like there is only one O2 sensor I have seen and it is directly below the exhaust manifold. I saw it and laid my hands on it because I was going to replace it but gave up. When buying the O2 sensor only upstream was available for 1987 Chevy V10 5.7L V8.)

 

[Redfish]

It appears the catalytic converter is not required on a vehicle as old as mine, or any of ours, here in VA.
If deleting the cat won't mess with the driveability of the truck it is the cheapest option. (It seems like there is only one O2 sensor I have seen and it is directly below the exhaust manifold. I saw it and laid my hands on it because I was going to replace it but gave up. When buying the O2 sensor only upstream was available for 1987 Chevy V10 5.7L V8.)

@legopnuematic is correct and so are you. There is only one O2 sensor and it is upstream of the catalytic convertor. I simply meant that with the extra air pumping into the exhaust and no cat to burn the excess fuel you may hear some popping and backfiring. Mine did until I completely blocked the air from the smog system.

 

[JamesSam]

I appreciate the feedback from you all. This is helping me decide what to do next.
I already have the drivers side sender and a new tank to pick up.
I don't know if the cat is even the problem but I suspect it could be. Initially I was going to examine when taken out and clean it if not destroyed as stated earlier, but it is proving difficult to remove without cutting.
I suppose if I cannot pry it, I will just cut it out examine, then determine straight pipe, or dropping another $150-$200 for a new cat if necessary.
A hundred bucks here, a hundred bucks there, it's just money, right!!! What does it matter now. Lol. Help me Jesus. Help me Tom Cruise.

 

[JamesSam]

Now I just want to keep binging the OJ documentary on NetFlix let alone work on my truck or any of the other thousand things I gotta do today.

 

[bucket]

I appreciate the feedback from you all. This is helping me decide what to do next.
I already have the drivers side sender and a new tank to pick up.
I don't know if the cat is even the problem but I suspect it could be. Initially I was going to examine when taken out and clean it if not destroyed as stated earlier, but it is proving difficult to remove without cutting.
I suppose if I cannot pry it, I will just cut it out examine, then determine straight pipe, or dropping another $150-$200 for a new cat if necessary.
A hundred bucks here, a hundred bucks there, it's just money, right!!! What does it matter now. Lol. Help me Jesus. Help me Tom Cruise.

I certainly do not believe that the cat is your issue... BUT, it is the original pellet style cat and it's restrictive by nature. And it's in your way, so cut it off.

Since your cat is still the factory part, you can take it to a recycler and they will typically pay you 40-50 bucks for it. Some factory cats are worth 100+, but not the pellet style. And aftermarket cats have zero value at a recycler.

But anyway, sell your old behemoth that is in the way, and put that money towards a new, modern style replacement. I'll bet they are cheap on Rock Auto.

 

[legopnuematic]

The cat off of the 79 was full of rust I guess, it was heavy, brought it to the local recycler, I feel like they kind of just make up a number, one person looks at it (no weighing or inspecting), says let me talk to the manager, comes back a couple minutes later. $140 for it, sure. That was 2020, so maybe they were at a high then. Same place I took the one from the 76 in 2017 and got $20 for it lol. Both pellet converters.

 

[idahovette]

Maybe @78C10BigTen Ted, would know what the old cats are worth?

 

[JamesSam]

At Oreilley's to pick up my new tank and sender. I guess I'll ask about the pipe cutter and see about a new cat.

 

[JamesSam]

First pic is cab side of the cat second pic is the bed side of the cat. No way I can get in there to the tank bracket bolts with it in place.

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[Redfish]

First pic is cab side of the cat second pic is the bed side of the cat. No way I can get in there to the tank bracket bolts with it in place.

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We are tired of your negativity. This is a Can Do group. We expect results, we expect improvements and we do NOT want to hear (read) "I Can't".

Grab a sawzall, a cutting torch, an 8" sidegrinder, grab a Stihl chainsaw if you have to. Cut that offending, restrictive, ugly, heavy power robbing, environmentally friendly piece of catalytic converting garbage out of the way and get this tank dropped. We want this d***ed truck to RUN. We want to read that you are having issues with traction and excessive tire wear due to the uncontrollable horsepower boost you got from removing that catalytic garbage and installing the new tank and pump.

For extra points stop on your way to wherever you go to sell the old catalytic convertor, find a Vegan person and beat them viciously with it.

Good Luck! Seriously, I am looking forward to a good result soon.

 

[JamesSam]

We are tired of your negativity. This is a Can Do group. We expect results, we expect improvements and we do NOT want to hear (read) "I Can't".

Grab a sawzall, a cutting torch, an 8" sidegrinder, grab a Stihl chainsaw if you have to. Cut that offending, restrictive, ugly, heavy power robbing, environmentally friendly piece of catalytic converting garbage out of the way and get this tank dropped. We want this d***ed truck to RUN. We want to read that you are having issues with traction and excessive tire wear due to the uncontrollable horsepower boost you got from removing that catalytic garbage and installing the new tank and pump.

For extra points stop on your way to wherever you go to sell the old catalytic convertor, find a Vegan person and beat them viciously with it.

Good Luck! Seriously, I am looking forward to a good result soon.

Yes Sir! Working on it Sir! Lol. I am planning to borrow a saw zaw from a friend or my father in law and getting to the tank.

 

[brooksman9]

https://www.harborfreight.com/power-tools/power-saws/reciprocating-saws/10-amp-variable-speed-reciprocating-saw-56250.html