2000 Cadillac Escalade Have No Idea-Fuel maybe??

I forgot it does sound weird when running (driving it only...just sitting there its fine) and I can't go above 30 mph.

Can you describe the sound it makes? Also, have you checked the fuel pump pressure? Finally, has the check engine light come on?

The sound it makes is kinds of like a car with no muffler but not as loud. It always sounds that way due to the type of muffler or engine something (sounds tuff) but this is different. I check the fuel pump pressure and it is at 61 they said and that it should be at 80+. Also, today when I killed it to go into the store, it acted like it didn't want to start when I tried to start it. It eventually did start but was if(y). I'm replacing the fuel pump today so hopefully that works. Do you think it could be it?

Since it sounds funny, are you sure the catalytic converter isn't plugged?

Well I actually thought about that several times. But everyone I talk to says to try the fuel filter, plugs, pump...everything but that. I was told I could just poke a hole in the catalytic converter and others are saying no to just have it cut off. I don't know what to do. If the fuel pump doesn't fix the problem then that (catalytic converter), 02 Sensor or EGR Valve is next in line. Which I try first?

Okay well I changed the fuel pump and its the same way. I was told that since the check engine light is on, that if I unplug the battery for awhile then reconnect that it will tell the "brain" that its okay and the engine light will off, resulting in a fix maybe. Does that sound right?

Wow... someone is telling you to cut the converter off or punch a hole in it? Not very good ideas. As far as the check engine light, it may go out, but in most cases the computer needs reset using a scanner. Most parts stores will do it for free. However, I don't think that will fix the problem.

Do you have any ideas what will fix it? Another guy told me it could possibly be the timing sensor or something. Do you think that is a possibility? I just need it fixed asap.

Unbolt the catalytic converter and see if that takes care if the issue. Don't cut it or put a hole in it. As far as the timing issue, there is no "Timing Sensor". You have a crank and cam sensor. Usually the vehicle won't run when either goes bad. Try the converter first.

Okay. Well I will try that. Also, another mechanic is coming to look at it today and says it could a box thing that sits by the engine. He knows what the box is called, but I can't remember the exact name.

Let me know what you find.