Rough Idle with stall

Hello,

6 months ago I bought my 05 envoy that currently has 90k miles on it. I have a lot of symptoms that all started around the same time.

the problem started with a rough idle that was pretty noticeable.Next came the engine stalling at red lights. This has happened several times. A week or so after the engine stall I noticed "hair" coming out of my tale pipe. Im not familiar with the vehicle but I am assuming that means my resonator is in the process of blowing out its packing.

Today it did something i have never noticed. I was driving, saw a cop and immediately let off the gas and gave the breaks a quick stab. When i did this i noticed the spedometer dip about 30 mph and then resume back to normal.

I know this is a lot of symptoms but I am wondering if some of them are related.

This weekend when I have some time I am going to try and clean the throttle body. Are there any tricks to this. I have also already replaced all 6 spark plugs, one had oil on it. Also does the resonator losing its packing present any problems.

Any help with my many problems would be much appreciated.

What you describe is usually caused by the TB, but other things can do this, start with cleaning the TB. That hair as you describe is not from the muffler.

I plan on cleaning the throttle body this weekend when i have some time. How do u explain the speedometer jumping so crazily. Also, if the fiberglass isn't from the muffler. Where is it from and should I be worried about it?

You could have the exhaust back pressure tested thru the 02 port to see if there is any blockage, the speedo head in these trucks went bad quite often.

I am guessing the back pressure test is something that a mechanic would have to do?

Yes I would say so.