Hello,

Slightly different question to the usual questions.

When I purchased my 93'FD it had a stonking big stainless steel exhaust on it. It was basically a big back box with a tube right through to the down pipe.

Now I couldn't live with the noise and the smell of fuel, so I have replace it with a Magnaflow hi flow cat and a quieter back box.


The cat was advertised as replacing the stock unit, so I thought great, easy fix.

When I was fitting the new system yesterday I found the air pump line pushed up out of the way. So I pulled down and found that the hose had been plugged with a bolt.

So I have 2 questions

1. I have rigged up the air pump hose to the cat. The factory connection has a small hole in the end, which I assume, restricts the flow into cat. I have just rigged up the full bore rubber pipe onto the cat as it just had a 10mm dia pipe coming out the side of the cat and not the factory fitting.

Will this extra flow of air into the cat cause an issue??

2. Considering the hose from the air pump was just blocked off with a bolt, would the person that disconnected it have done anything else to stop the pump working. I cant see any plugs disconnected.

After putting everything back together I realised that I had not made sure there was air coming out of the pump and in to the cat.

Sorry for long winded post, but would really appreciate any advice.

Daniel

 

Sooo, I've took advantage of the break in the rain to continue playing.



I've been looking at the air pump further and to be honest I don't know if its working or not after I reconnected it.



The grey plug on top was connected, the wires at the plug do look a bit bare and heat ravaged, but I am getting 12v at the plug. I've checked the fuses and I've swapped the relays around to see if I can see a difference when the engines running.



What happens when the pump kicks in or out, can you see or hear this happening?



As far as I can tell all the previous owner did was stick a bolt in the hose in to cat to block it off. Could this of damaged the unit.



As always any help appreciated



Daniel

 

IIRC, the AP only operates during (relatively) low rpm...I think it shuts off around 3800 rpm but I think you can check that in the Factory Service Manual. So regardless of how the lines are re-attached, you shouldn't have to worry about too much air to the cat. And if the PO only plugged that line, I doubt any permanent damage was done.