Catalytic Converter?

[lilcallaway]

I have an e34 90' 535i. The weather dipped low and my car at highway speeds lacked a little pep. I assumed it was water in the tank. I used some water remover and nothing changed. The problem got a little worse and I assumed maybe it was the o2 sensor as I couldn't remember if I had changed it after buying the vehicle. It took a little while for me to get around to installing it and in the meantime the problem had gotten worse with the engine light coming on periodically. I changed it and nothing different. I then assumed maybe the low power was due to a faulty fuel pump. Changed that and nothing. I changed the fuel pressure regulator for good measure and still nothing. After a horrible time getting back home, I look under the car and the cat is glowing red hot. I've heard about it, but had never actually seen that before. Can something else be the problem or should I just change out the cat? Also, I've done a search about the magnaflow cats. Are they really ok to use?
Thanx in advance....

[632 Regal]

anytime you change anything out reboot the computer, once it is in fault mode it will continoue without a reboot. Plus afre a reboot you can check any new faults.

HTH

[Bill R.]

If the cat is glowing it is getting unburnt fuel into it... so either you have an ignition misfire thats not burning fuel and dumping it raw into the cat or you're getting way too much fuel and its not all burning with the same result.... If you put a new cat in you'll just melt it unless you solve the problem first. Check the codes to find out why the light is coming on. do the stomp test and see what code/codes are coming up. Don't waste your money on a cat yet.







I have an e34 90' 535i. The weather dipped low and my car at highway speeds lacked a little pep. I assumed it was water in the tank. I used some water remover and nothing changed. The problem got a little worse and I assumed maybe it was the o2 sensor as I couldn't remember if I had changed it after buying the vehicle. It took a little while for me to get around to installing it and in the meantime the problem had gotten worse with the engine light coming on periodically. I changed it and nothing different. I then assumed maybe the low power was due to a faulty fuel pump. Changed that and nothing. I changed the fuel pressure regulator for good measure and still nothing. After a horrible time getting back home, I look under the car and the cat is glowing red hot. I've heard about it, but had never actually seen that before. Can something else be the problem or should I just change out the cat? Also, I've done a search about the magnaflow cats. Are they really ok to use?
Thanx in advance....

[Tiger]

Agreed... leaky injector will cause this problem. Also check ignition system... like your wires and distributors. When you pull out your spark plug, it will tell you which injector is leaking and/or which cylinder is misfiring.

After all that is fixed, then you can change your cat converter... right now, it is clogged.

[Ross]

You can check for a clogged cat with a vacuum gauge. Holding the revs STEADY at 2k or so watch the reading on the gauge, if the needle begins dropping that is an indication of restricted exhaust. Unless your tailpipe is bent over double you likely have a clogged cat.