(I Re-posted question, first was in old reply)

I just started same prob(svce eng. soon light on)with my 2001 ETC. A local parts store "tech" hooked up a code reader and got " lean cond. bank 1, bank 2". He pointed to a cylinder shaped casting with one elec. connector, I believe on the throttle body. Is this the MAS(sensor)?. He called it the "idle mixture control valve."

I pulled up on the dash : PCM P0171 CURRENT, PCM P0174 CURRENT, RF U1064 HISTORY.

I sprayed starting fluid after removing the induction cover, and I guess idle may have increased slightly around throttle body hose clamp for a millisecond, but it`s tight as hell.I visually inspected vacuum tubes and all look like new. BUT I swear I hear a vacuum leak, andI don`t remember hearing hissing b4. I`m extremely **** when it comes to my vehicles/mechanics in general.

Conditions are: svce. engine soon light on, after starting and after rev down(stop at red light), idle remains at 1000 to 1200 rpm for 5-10 sec.
P.S. Twice since I owned etc, I had no radio and no "Key in ignition chime" until driving, shutdown, restart a few times. I bought the GM repair manuals for my vehicle. Now I need a manual for the manuals. lol

Any help would be appreciated
Mick

 

Check rubber boot between plastic intake manifold and aluminum housing that throttle body attaches to. Hole can burn thru it at bottom. Part is called plenum. Intake has to come off to replace it.

 

Thanks, I`ll look again more thoroughly.

Do you think I`d be able to "feel" a leak at or off idle w/my hands? I may be wrong about the vacuum sound volume, but it seems louder than it was.

I just got done checking the MAS sensor. Had 1 little spec of dirt that I picked out w/a pin. Any possibility it can be an o2 sensor or even a fuel filter??

Thanks,
Mick

 

Assuming you do not find what slowroll mentioned, open the service manual and do the diagnostics related to the first current fault code PO 171. Once thats fixed, erase all codes and drive it. then report back on what it took to fix it. The advantage of on board diagnostics and fault codes is you no longer throw parts at a car nor do you mull over what it "might" be. The lean condition is affecting both banks equally so the intake is a good bet.

 

I`m not totally sure how to do diagnostics. I have no scan tool myself. I just pulled codes off the onboard system. Is this possible on board?
Then again I just dropped car at my local dealer. Can`t relly afford whatever they want, but I don`t want to do any damage. Manual is kind of "cryptic"
Thanks

 

Thanks guys. I`ll report back on what it was.(and how much it was.) I`m psyched on getting reading to not be so timid with the on board system. I`d like to at least learn how to clear codes.
On my `92 eldo, I was a little bolder.

My next job will be adding bose changer, which I just posted question. (in another "thread?")

Thanks, I`ll post my problem fix,
Mick

 

Just picked up car. "Slowroll" nailed it.Leak inplenum. $48 part. About $350 to install it. I added trans and ps flush,and induction svce.,and it about doubled. Oh well, I`ve always loved my caddys.
Now if someone can steer me towards info on picking up an original model Bose changer for trunk mount, if possibility for me to add to my system w/o any probs, I`d also appeciate it.
Thanks to all,
Mick

It`s 12 mid., and i`m editing this post.Just got up after posting earlierand passing out after rough day at work. Was too beat to drive much after picking up earlier, but now I`m throwing on some sweats, and going to "tool" around town for a bit. Haven`t done this in years!
Maybe I`ll find some "hotshot" Honda or Mitsubuishi teen punk on the road that`s trying to show off in front of his hot little cheerleader girlfriend that wants to RUN!!
P.S. What exactly is this "WOT" thing you guysalways talk about??? haha
I`ll let you know who gets the girl.(don`t hold your breath)
Ain`t gonna be no "Cadillac Coffin"

just heard my little bro`take off inhis(my old) `92 eldo.