Fixed All Problems In One Shot!

[DSN46]

Hey Guys/Gals,

 

Didn't know what to title this post exactly. Hoping someone searching will search entire thread and not just titles.

 

Okay, I was having the following problems:

1. Engine stumbling at idle. Not really rough.. just stumbling every few seconds.

2. Bad fuel economy (I know... it's a Tahoe with 35's..but it was worse than it should be.

3. HORRIBLE vibration noise... more like a "screeching" only at certain RPM's.

4. NO CEL lights or codes thrown by PCM.

 

I threw parts at this thing for the engine stumbling left and right. I tried welding the heat shields in different places and even bailing wire at one point to stop the vibrations and screeching. I spent $700.00 getting an exhaust manifold bolt that had broken off replaced along with new donut gaskets at the Y pipes. Man I couldn't figure it out!

 

THEN.. one day I pulled one of my upstream O2 sensors. Held it my hand and shook it real hard... it RATTLED! So I pulled the other one and it did the same. Replace both and ALL the aforementioned problems ceased.....

 

Seems the ceramic inside them had busted and was useless for the engine and vibrating to a screeching sound at just the right RPM's.

 

I can't believe something so easy was the cause of my frustration.

 

At any rate, if you are having any "weird" problems and cant seem to nail them down, try pulling one of your upstream sensors and see if it rattles when you shake it... it shouldn't!

 

Hope this helps someone else out.

 

Thanks,

 

James

[2000DV4.8]

I'll have to check that out, maybe it's more than just my cats rattling.

[DofD]

That's great that replacing the O2 sensors fixed all those issues! Have to add that info to the ol' repository of knowledge.