How do I check if I have a blocked cat?

[cello2119]

Hey my 85 318i bogs out at 4000rpm and seems to have a much larger gal between gear changes than other same model e30s I have driven. I reckon the reason could be a blocked cat. Do I have to take the whole exhaust from the headers off? Or can I just cut off the cat and then wield it or a new one back on?

[MaxBell]

Just look through the tail pipe. If you can see light than there's no blockage! :)

[cello2119]

Just look through the tail pipe. If you can see light than there's no blockage! :)

Thanks man

[2mAn]

I highly doubt your problem is the cat... and I think the canadian was messing with you

[rommaster2]

Generally a blocked cat will result in worse performance all across the board, like an engine that struggles to rev at all.

Does it rattle? Every time i've dealt with a clogged cat it rattled like crazy and was clogged because a loose chunk got stuck in the output.

[cello2119]

Generally a blocked cat will result in worse performance all across the board, like an engine that struggles to rev at all.

Does it rattle? Every time i've dealt with a clogged cat it rattled like crazy and was clogged because a loose chunk got stuck in the output.

No it doesn't rattle, I changed both fuel pumps, AFM and injectors so I'm suspecting its the fuel pressure regulator now

[cabriodster87]

drill a hole ahead of cat, take pressure reading. any thing more than say 3psi is restricted.

[Mike]

Take a temperature reading

[Swanny]

How do I check if I have a blocked cat?



Xrays


If you love where they don't smog cut it the hell off anyway. Racecar.


Also, how is your timing and any vacuum leaks?

[Ether-D]

^ Dammit, I was workin' a badass response on this order...