Is there a way to do SSI + cat + O2?

[tirwin]

I saw a post by Craig_D recently that really got me thinking.

Look at post #5 in this thread Post Pictures of Exhaust

I really like the way he's incorporated dual cats with SSIs and a 2in/2out setup. Also love the sound.

I'm just wondering if there is any way to incorporate an O2 bung into this setup. It looks like SSIs used to be made with an O2 bung option although I guess you're only getting one bank of cylinders. I guess there is some reason why the SSIs with the O2 bung are NLA? Anybody have any other ideas on how this could be done?

My car is an '83 SC w/ factory exhaust. (Almost identical to Craig_D's in fact except no duck.) Might be able to live without the O2 bung on the CIS. Mainly just wondering if it's possible to do this. Kicking around ideas at this point.

[JAR0023]

I don't see any reason you couldn't. Any competent muffler shop can add in an O2 bung to your chosen exhaust. The factory 3.2 cat is set up so the O2 sensor is only reading one side of the exhaust. It's before the merge on the collector. -J

[will hung]

That stinks about the O2 sensor. When I bought my SSI's a year ago, I ordered them with the O2 bung already welded on for that day I finally make the jump to EFI. In the mean time, I just plug it. There are several companies that sell O2 bungs and any welder can drill the hole and weld the bung into place. I went back and forth on whether I should buy my SSI's with or without the O2, but in the end found out that the option was much cheaper than adding it later.

[Chuck.H]

I have SSI's with an O2, and yes it just gets one bank, but if all is working correctly that's enough to monitor the A/F ratio.

BTW, I have an O2 bung in both SSI's, I use the second one for my wideband O2 sensor when tuning. I don't let the WEGO sit in there, I have an old sensor in there most of the time.

Chuck.H
'89 TurboLooKTarga, 341k miles

[Craig_D]

Hi tirwin, thanks I'm glad you like my setup. I absolutely love it and feel good about running a clean hot rod.

Buying SSIs with the bung is going to be useless because that part of the SSI pipe is thrown out. I don't think folks are looking at my dual Cat setup pics.

You'll want to add the bung somewhere down stream of the merge collector, but it's very tight and there are the V-band flanges to contend with. I'm not sure if you need to have the sensor before or after the Cats (I don't have the sensor on my '78), but if you can run it after the Cat, the best place would be on one of the pipes going into the MagnaFlow or whichever muffler you choose. Mind you, there are different body lengths for that MagnaFlow, and we chose the 18" unit for sound. The 14" would have given us more room, as would smaller Cats, but we were going for highest quality emissions, and best sound while also going for best power. We achieved those goals, but it was/is a tight fit.

I'm happy to get you part numbers and answer any questions you might have.

Cheers,

- Craig_D

[tirwin]

Originally Posted by Craig_D

Hi tirwin, thanks I'm glad you like my setup. I absolutely love it and feel good about running a clean hot rod.

Buying SSIs with the bung is going to be useless because that part of the SSI pipe is thrown out. I don't think folks are looking at my dual Cat setup pics.

You'll want to add the bung somewhere down stream of the merge collector, but it's very tight and there are the V-band flanges to contend with. I'm not sure if you need to have the sensor before or after the Cats (I don't have the sensor on my '78), but if you can run it after the Cat, the best place would be on one of the pipes going into the MagnaFlow or whichever muffler you choose. Mind you, there are different body lengths for that MagnaFlow, and we chose the 18" unit for sound. The 14" would have given us more room, as would smaller Cats, but we were going for highest quality emissions, and best sound while also going for best power. We achieved those goals, but it was/is a tight fit.

I'm happy to get you part numbers and answer any questions you might have.

Cheers,

- Craig_D

Thanks, Craig! I didn't notice that part of the SSI pipe is thrown out. The O2 bung is normally installed pre-cat. Hmmm... have to think on that some more.

One thing I noticed in your pics is that the cats look like they are hanging down a bit. Maybe it's just the perspective in the picture? Has that ever been an issue?

I'd love to get your part numbers -- PM me or post them here if anyone else is interested.

I kinda dig this exhaust pipe on the Singer too.