Could clogged cats cause a quiet 'popping' sound?

Myco

Myco

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I'm getting a popping sound from the engine. It doesn't happen along with the running of the engine juuuuuust every once in a blue moon it will quietly 'pop'. Sounds like a bubble coming up out of water or something.

If it is a clogged cat does the gen II mark pass inspection with the back cat(s) gutted?
 
If it's a clogged cat it's probably "not the rears"... it'll be the fronts.

ALSO that sound you describe sounds like a busted, leaking EGR tube.

I turned off my rear 02's ( as a test) and my car passed inspection.
I promptly turned them back on, I just wanted to know if the car would pass without the rear 02's here in houston..and it did.
 
give me heads-up on what an egr tube is. anyone? thanks
 
EGR= exhaust gas recirculation
the tube is on the drivers side exhaust.
It connects the EGR VALVE to the exhaust system.

it's very common for them to crack/split and make a "sputtering" or a "sput-sput" sound.
 
My 98 makes a noise simliar to what you have discribed. It sounds like it is coming from the air intake on mine. Almost like a miss at idle. Only at idle do I notice this, much to quiet to hear at off idle. It may go away off idle? Have you noticed any performance change.
 
htrdlincoln98 said:
My 98 makes a noise simliar to what you have discribed. It sounds like it is coming from the air intake on mine. Almost like a miss at idle. Only at idle do I notice this, much to quiet to hear at off idle. It may go away off idle? Have you noticed any performance change.
Click to expand...

Mine seems to be on the same side. I've walked around the car and tried recording it and I found on the front pass. side it was loudest. :dunno:
 
Yeah pop the hood and listen near the air filter. Its most likly coming from there. I thought it to be a mis fire. I'm not fixing a car thats not broke. Runss very well for itself.
 
Idle noise

I've heard the same noise on my 98 many times. Sounds like a misfire or bubbling noise in air snorkel at idle only. Otherwise I get 28 or better mpg. Recently put in a battery and re-learned computer. Seems to have subsided last I noticed. Have to check again in a day or so.
Also have read other posts as to same observations by others, that noise.
 
haven't noticed on mine but on MWB's bird we heard this type of noise and we traced it to the charcoal canister in the front bumper. gen2's have them in the rear under the trunk, not sure on a gen 1, but its a possibility.
 
Did you ever figure out if it was the egr tube? My 95 is doing the same thing.
 
htrdlincoln98 said:
My 98 makes a noise simliar to what you have discribed. It sounds like it is coming from the air intake on mine. Almost like a miss at idle. Only at idle do I notice this, much to quiet to hear at off idle. It may go away off idle? Have you noticed any performance change.
Click to expand...

1969350 said:
I've heard the same noise on my 98 many times. Sounds like a misfire or bubbling noise in air snorkel at idle only. Otherwise I get 28 or better mpg. Recently put in a battery and re-learned computer. Seems to have subsided last I noticed. Have to check again in a day or so.
Also have read other posts as to same observations by others, that noise.
Click to expand...

Mine too...
 
3 of my gen 2 motors have made this sound in two different cars never really investigated it
 
Unlike some in this thread I am getting 13mpg city and around 20 highway. Need to find out wth is going on. I haven't investigated this. About to drop 250$ on new suspension parts and put them on. If it doesn't effect gas milage and isn't going to cause the engine to throw a rod through the oil pan I'm fine with it's 'personal' noises.
 
mine does the same thing always wonderd what it is. I will have to check the egr tube.
 
If you have a Gen2 with a cobra intake and use just a hose from the IAC to the intake snorkel this sound will be much more pronounced. If you used the hose from a cobra it will have a one way light pressure valve that little black box with the right angle bend. Sometimes at idle the IAC will modulate quickly and cause a almost like back fire sound from intake snorkel, the valve from the cobra acts like a muffler and valve, on the Gen2 the IAC passage is integrated into the manifold and the sound should be almost un-noticable.
 
Tiltedhalo said:
If you have a Gen2 with a cobra intake and use just a hose from the IAC to the intake snorkel this sound will be much more pronounced. If you used the hose from a cobra it will have a one way light pressure valve that little black box with the right angle bend. Sometimes at idle the IAC will modulate quickly and cause a almost like back fire sound from intake snorkel, the valve from the cobra acts like a muffler and valve, on the Gen2 the IAC passage is integrated into the manifold and the sound should be almost un-noticable.
Click to expand...

I haven't noticed any change with the noise sense the cobra intake. I didn.t buy the corba specific IAC tube?
 
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