no power, load intake, quiet exhaust

[bob442]

EDIT: I ment *loud intake*

Hey guys, can't seem to pin the problem as a LIMG, right now my problem is today, as of after work, my car is extermly quiet out the exhaust and loud on the intake, has no power, i can hear a slight hissing sound, but i cant seem to track it, even with propane. Can anyone help me with the diagnosis? my car also has balls for power. 05 montecarlo 3400 sfi, stock aside CAI and exhaust.

Bob

[86FieroSEv6]

Sounds like a clogged cat. . . . . . temporarily remove O2 sensor/s and see if power improves, if it does then there's your culprit. Removing the O2 will relieve backpressure if that's where your problem is.

[bob442]

i have a straight through exhaust, and its usually very loud, and right now it sounds like a stock 3100 beretta out the tail, and i'll add theres 80000km on it

[86FieroSEv6]

Hmmmmmmmmmmm . . . . I wonder what kind of pipe was used. If it was double wall pipe it could be that the inner wall collapsed. Or possibly a baffle in the muffler broke loose and is restricting the exhaust. Another possibility is lack of fuel volume. In any case, a couple of tests are in order to check the basics. You may have to visit a competent shop for some baseline analysis. I'm afraid that's about all I can muster from way down here without more clues.

[bob442]

well thank you for your input, i'll have to see if i can pull it in the shop tomorrow, or atleast run the scan tool on it, heck, it might be the fuel pump, it was acting up alot with starting till lately, usually it wouldnt start after prolong driving right away, have to cycle the key once to get it going. none the less, its a big problem, and i'm afraid i could be leaning it out.

[86FieroSEv6]

Kewl, let us know what you find out.

[Tbay99Venture]

Did you do a vacuum reading? That ought to help rule some things out.

[bob442]

it ended up being the cat. the car was still under warranty. apperantly they have to get one from arizona or something, and i'm from canada... so if it isnt here in a few days, i'll op. maybe for an after market one.

[bszopi]

If you have a striaght through exhaust, as you said above, how could it be the cat? That was what was mentioned originally, then you responsed that you have a straight-through exhaust.

[robertisaar]

If you have a striaght through exhaust, as you said above, how could it be the cat? That was what was mentioned originally, then you responsed that you have a straight-through exhaust.

X2....

and how the hell are people plugging monolithic convertors anyway?

between two 660s, i'm up to 359,647 miles, both on their original cats, both fed piss-poor, cheap 87 octane fuel and neither show any kind of sign that the cats are going...

it confuses me.

[IsaacHayes]

The impala's and MC's have an issue with the cats.

I was going to say cat. You might even hear clicking on the HWY as the springs on the downpipe spread apart and then slam back together from the back pressure.

The issue is there is some sort of insulation that breaks free and then goes in front of the cat core and clogs them up. My friends 02 Impala had this happen.

[pocket-rocket]

X2....

and how the hell are people plugging monolithic convertors anyway?

between two 660s, i'm up to 359,647 miles, both on their original cats, both fed piss-poor, cheap 87 octane fuel and neither show any kind of sign that the cats are going...

it confuses me.

Both the 91 and 92 broke the catalyst material loose from the stuff that holds it in place from the lopey idle because of my cam timing so they both started to rattle. The 91 had ~165k on the original cat, the 92 had ~140k?