Old O2 question

[GPster]

The Jeepster is actually a re-bodied '87 GMC S15 truck with a 2.5L four. It is a TBI engine that was not California built and will be running on it's stock computer and it's original instrument panel. When I drove this thing out of the junk yard and stripped it the catalytic converter had already been stripped (no surprise or concern). Piecing this thing back together I find out that the O2 sensor is in the exhaust manifold not in the pipe near the converter. Taking the sensor plug out of the manifold left me with pieces and a hole in the manifold. My plan is not to run a converter because it would need to be right where I had to build the "K" member that I had to build to support the transmission. Some information I have seen is that the older O2 sensor may not have much to do with the engine's operation but mostly acts to activate the "check engine" light. Can I just use the broken O2 sensor bulb mount to make a plug for the exhaust manifold or am I going to have to find a 30 year old exhaust manifold to replace the broken piece so I can get the O2 sensor to work when I want to get the engine running. Just trying to get my chores in order. GPster

[kb426]

My first though is to replace the manifold. Second is to install a bung as close to the location of the original as possible. From what I have seen, it's very important to have the sensor in operation.

[Crosley.In.AZ]

Exhaust tubular  manifold on eBay for 50 dollars. Claims to be new. Fits 1982 - 92

Port for o2 sensor

[papastoyss]

Muffler shops usually have the bungs in stock.As KB said, weld the bung to the exhaust pipe as close to the manifold as possible. Tho o2 sensor isn't as important in OBD-1 (pre 1996 single wire) as later OBD2 applications but there isn't any real benefit in deleting it.

[tomslik]

Muffler shops usually have the bungs in stock.As KB said, weld the bung to the exhaust pipe as close to the manifold as possible. Tho o2 sensor isn't as important in OBD-1 (pre 1996 single wire) as later OBD2 applications but there isn't any real benefit in deleting it.

maybe not AS important as obdII but still important.
it's the main input to the computer for fuel mixture

[GPster]

Thanks! All of the comments gave me parts of the answer that I needed. I've seen prices for replacement catalytic converters and I thought all of the smog related pieces would be expensive so I hadn't even checked price and availability. Around the time that I stopped working on cars in favor of motorcycles people were eliminating catalytic converters as a practice. So I was not surprised when my donor truck didn't have one. The other day I Googled the O2 sensor for this application just to see what it looked like so I could understand if I could use the pieces of my broken part to make a plug for the hole in the manifold.  The second item on the page was a plug for the manifold. They wanted almost $9.00 for that plug. Looking further down the page and I could buy a replacement O2 sensor as cheap as $15.00. Not wanting to deal with on line shopping or shipping I just went to Advance an bought the replacement part. So this much will be done correctly. I want on step further while I was at the computer and I looked up the catalytic converter. Shopping around I saw prices as low as $35.00. So that's not out of the question. Part of my initial question deals with the catalytic converter. Because the C2 sensor is in the exhaust manifold which is probably 4 feet from where the converter was in the stock application does it really necessary? On the Jeepster due to the "K" member it's probably going to be an additional 2 feet further away from the sensor. GPster

[papastoyss]

Thanks! All of the comments gave me parts of the answer that I needed. I've seen prices for replacement catalytic converters and I thought all of the smog related pieces would be expensive so I hadn't even checked price and availability. Around the time that I stopped working on cars in favor of motorcycles people were eliminating catalytic converters as a practice. So I was not surprised when my donor truck didn't have one. The other day I Googled the O2 sensor for this application just to see what it looked like so I could understand if I could use the pieces of my broken part to make a plug for the hole in the manifold.  The second item on the page was a plug for the manifold. They wanted almost $9.00 for that plug. Looking further down the page and I could buy a replacement O2 sensor as cheap as $15.00. Not wanting to deal with on line shopping or shipping I just went to Advance an bought the replacement part. So this much will be done correctly. I want on step further while I was at the computer and I looked up the catalytic converter. Shopping around I saw prices as low as $35.00. So that's not out of the question. Part of my initial question deals with the catalytic converter. Because the C2 sensor is in the exhaust manifold which is probably 4 feet from where the converter was in the stock application does it really necessary? On the Jeepster due to the "K" member it's probably going to be an additional 2 feet further away from the sensor. GPster

If you don't have to pass an emissions test to tag this vehicle you can forget about the cat converter unless your tree hugger vibe is kicking in!

[GPster]

If you don't have to pass an emissions test to tag this vehicle you can forget about the cat converter unless your tree hugger vibe is kicking in!

This thing is titled as a '48 Willys Jeepster and will be licensed that way (if I can find somewhere to stamp the numbers).We don't have to deal with "Sniffing" so that shouldn't be a problem. I hoped that the answer would be this simple. Now to get back at getting it running. GPster

[Beck]

GPster, You are following the path I would have taken. Install the O2 sensor and let the converter off.

Some of the cheap O2 sensors are just that, cheap. I would give it a try with what you have purchased. The O2 sensor I need from Holley is $238.