OK, I won't go into this fiasco I've been chasing for months. Just this sqeak I heard at idle and rough idle, and other issues. I thought it was the CHIRP people mention that preceeds a CAM SYNC failure. I replaced the CAM SYNC (290Kmiles). It wasn't visibly bad but...I'm glad I replaced it. The noise was still there and on the drivers side of the engine. It sounded like a vacuum leak but I could not locate it. I spent hours looking, friends did a smoke test, removed the plenum, found nothing. I was just thinking about replacing all the vacuum lines and I thought...why am I thinking RUBBER. Metal parts crack and can leak just as well.

I wanted a stethescope so I could find the noise, Like I said, I"ve spent hours under the hood, removing parts,etc... So the EGR line from the EGR to the EXHAUST has insulation over it. IT's metal...maybe. Sure enough...the line is cracked and air is escaping/entering. NAPA sells the line.

So...check that line out.

I had some EGR codes, I tested and checked the EGR, even make a block off gasket. What the cracked line would do is make the engine computer think the EGR was leaking and it would occasionally give that code. I'm no great systems tech but...That leak may throw off the O2 sensor and make the computer think fuel was not burning properly and adjust the fuel injection accordingly. This leak and O2 sensor being on the driver's side is the same side I have leaning issues on injection. This may or may not solve the problem but I've done just about everything else...changing a bad part certainly won't hurt.

Good luck with yours,
Gene

 

Further deliberations....give me pause. I'm not sure this is the source of my problem but it is definitely cracked and air is escaping so....I'm changing it. :) Today,

Cheers,
Gene

 

Scratch that one. While the line neede replacing...it did nothing other than cure an exhaust leak. Move on folks, nothing to see here.... LOL