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....