Catalatic Converter (spelling?)

[Landon]

Lately ive been having alot of problems with my 93 325IS. When I gas it, it doesnt feel like the power is not going through the car, and it makes horrible sounds. I will floor it and see my RPM's go up..stop..up..stop..up.

I had a friend from work drive it, because she used to have a 93 325i. She said it was the Cat. converter, because she had the same problem.


I looked up the cat. converter and holy shit its expensive.


Then I had a few friends tell me, just get bypass pipes because its cheaper, and i'll get more performance and sound from my car. But illegal, but no one checks that in Florida.

Has anyone else have this same problem with there Cat. converter? And does just getting straight pipes a good idea?

[BMWspeedracer]

well, u could go the straight pipe way, but it'll most probably sounding a tad bit Hondaish. Getting an aftermarket seems like a better choice

['89 635 csi]

You will also loose all your low end torque.
I just put the cat back on my 5 and I couldn't believe how much more low end pull it gained!
You will gain a couple of horses, but what good is that if you lose your low end?!

[Landon]

hmm, I guess you are right, i dont have much low end power as it is. But when it does this im sure im waisting so much gas, I see my little MPG thing fly past 8 when it acts up.

I dont know to much about cars, what exactly is the cat responsible for?

['89 635 csi]

It's emissions related.
However the engine needs the back pressure that the cat delivers!

[Dirty_Tool]

Well hey lemme chime in here :P

First of all let me explain that the cat's job is to clean up the emissions coming from the engine and make for cleaner emissions out the tailpipe. Now Im on the west coast but I would assume Florida does have some kind of annual smog testing? If so then removing the Cat will cause the vehicle to fail the smog test.

Now your friend drove the car and said they thought the cat was bad because the car is unresponsive. If the Cat was plugged which is usually what happens when they bog the car down ... this is usually not an intermittent problem. I think you mentioned that the problem comes and goes. It can be intermittent if its breaking apart inside so a good check would be to get under the car and tap it with a rubber mallet and listen for pieces inside. Either way i would test it or pay to have it tested before replacing or bypassing it i wouldnt just take a friends word for it when the friend only drove the car and didnt do any other inspection or diagnosis.
There ARE several things which can cause this type of problem.

DT

[Landon]

Well, needless to say, after making this post I totaled my car out. It was my fault also....There goes my baby