hi all,

I finally got a wide band o2 sensor (bosch), but just looking from the top of the car, I don't see where there is space to weld a bung since the neck of the crawford cat is almost nil.

Has anyone put a bung on the down pipe itself? If so, how easy was it? Did you have to take the dp out? Was the welder able to reach from below?

I just didn't want to show up at the welder shop without any idea of how things are going to turn out.

thanks,
rob

 

Put the extra o2 bung right after the one that already on there .The cat is high up on the pipe and the o2 bung is closer to your exhaust . Just have them weld it in right after that one....Bill

 

booger,

thanks. just to clarify, put it right after O2 number 1, or O2 number 2 (behind cat)?

thanks,
rob

 

You have stock o2 sensors before and after your cats . If you want to put in a bung for a Wide band , put it on after the stock one on the drivers side . So you would end up with a stock o2 before the cat...a stock o2 after the cat....and then the one you want to put in...that would make 3 of them on the drivers side

 

There is just enough space on the neck before the cat for an extra bung. Doug put mine on the passegerside cat. I think you are better off putting it on the passenger side since the driverside space is more restricted. The passeger side cat is easier to remove too.
If you are going wideband it is supposed to be before the cat or you will get inaccurate readings.

 

thanks lorinserbenz and booger,

Thanks for your experiences, that's what I needed.

I didn't think the short neck before the cat was going
to work but since lorinserbenz was able to do it, then
that's how I'm going to have it done...

thanks again,
rob

 

I had mine [ with the RT cats ] before the cat . And now I have it after the cat [Crawford] . My readings from it now do not jump around as much . It is much more stable and easier to read because of that . My .02

 

I took it to a muffler shop and...

After all that discovery, the muffler guy said he could put
it on the neck of the crawford cat (too short). He said he
would have to removed the exhaust manifold to do it!

Uh, so I had him put it after the cat (so much for preparation...

thanks,
rob

 

If you do not have cats , ie. test pipes, does it matter where you mount your o2 sensor?

 

Everyone that I have talked to has said it needs to be BEFORE the cat to get an accurate reading.

 

I have the crawford CAts and intend to put the bung pre-cat on the Crawford , passenger side. There is room if a little of the CAT shield is cut away. If you shop can't do it , find one that can or send it back to Crawford Z, since his fabricator has done this multiple times.

The issue with post CAT readings is the A/F reading will "lag in time", the CAT incurs a memory effect. So when the thottle is first slammed the reading you get at (x) RPM will be slightly delayed with respect to what the cylinders see. So, before CAT is more valid.