just cut out the cat - now with pics!!

[birdman]

well the dealer i took the car to, to get it diag'd said it was out of time and the cat was restricted. well of the two, the cat seemed the easiest. ill not speak of how "easy" it was to get the cat out and some stright pipe in but when i looked through the cat i could see through it. does that mean it was or wasnt clogged, or is that not the way to tell. i also dont really like the way the exhaust sounds now but thats another story. does anyone know how to tell if its clogged? thanks.

[19902drlumina]

was the honeycomb still in there???

 

[birdman]

yea, it didnt look plugged i could see through it.

[19902drlumina]

run any better now? id guess if it was glogged u wouldnt be able to see threw it ive always looked under the car after a while of driving usually bright glowing

[birdman]

never really noticed a glowing but i havent driven it yet, had to eat. guess ill see what it does on the road.

[Hairdo12]

I would sait it is not clogged. Check your ignition system. Everyone thought my cat was clogged too... it even turned cherry red once and the exhaust smelled like shit. I pulled the cat off and looked through it and was able to see light through the honey comb. I too put a strait pipe in to test and had no difference except the exhaust smelled more. Turns out the ICM was not firing the 1 - 4 coil. Motor ran rough but still ran and it was sluggish as hell. Make sure you have spark at all 6 plugs. Oh and this never once threw a SES light and a computer scan won't pick it up.

[birdman]

well ive put a timing light on all the wires and all but 2 fired perfect, the other two had a kinda funny rythum but they were on different coils and when i swapped them and the icm with different ones it still did the same thing so i think my timing light is a little funky. i did pull the wires off once and just watched the spark and it lookd good so i dunno? i also just drove the car, it was louder and it didnt fix the bogging problem but it did seem to help slightly. cant wait until i get a good exhaust in there.

[DaveFromColorado]

USUALLY a glowing cat is not a sign that the cat is going bad, it's a sign of not all the fuel getting properly burned - ONE of the functions of the catalytic converter is to a catalyst to burn the rest of the hydrocarbons off before they enter the atmosphere - if too many of these hydrocarbons (fuel) are getting in there, the cat will overheat - this is usually why they clog up, but not a sign that they are already clogged.

 

overheating cat's usually mean either the ignition system needs attention (coil, timing, ICM, etc) or one (or more) of the injectors are stuck wide open, or your cam timing is way off (usually retarded, not advanced)

 

I'd bet, based on your symptoms,that it's either a failing coil, or a failing ICM - a failing ICM will give you an un-true spark, meaning it will be too advanced, then too retarded, and sparks at random times, a bad coil will USUALLY just be a weak spark.

 

Hope that longwinded response helps some.

 

--Dave.

[birdman]

well the thing is that ive swapped the icm and coils two or three times with no difference in drivability or anything. i do however have some doubts on the ecm, since iv replaced so many sensors with no progress and the ecm says remanufactured on the top, it makes me wonder.

[DaveFromColorado]

that too would lead me to believe the ECM is bad... fo' sure.

 

either that, or your timing is off on one or more of the cam's... if the belt did jump, that'd be a cause of the issues you're suffering from.

 

I'd verify the timing before tossing in any more money.

 

--Dave.

[birdman]

how would i verify the timing? pull the cam covers off and line up the flats? because i was going to do the timing anyway, but if its ok ill leave it.

[DaveFromColorado]

yup, I was thinkin' just checkin' the flats to make sure everything lines up alright.

 

--Dave.

[birdman]

well there is a delimma, first off the dealer i took it to said it was off but then he also said the cat was restricted which im not sure of. second off i hate redoing work so if i were to go as far as takinf the intake and valve covers off to check it i would want to just replace it because i dont know the last time it was done. ill have to think about this one.[br]Posted on: April 09, 2006, 03:28:23 PM_________________________________________________well heres the cat

didnt look that bad to me, not really rusted through or anything. and in person you can see through it better.

heres my temporary ghetto fix until i go and have an exhaust bent for it.

[DaveFromColorado]

you can always check the front bank without pullin' too much apart - and see if that one is off at all.

 

When tech's are diagnosing things like that, they see a heated up cat, and automatically assume it's plugged, because many of the dealership tech's are kids just outta college (because they are cheap labor)

 

the only way to truly test a cat (to see if it's plugged) is to put a pressure gauage in front of the cat, and behind the cat, and measure the difference in pressure from just before, to just after at WOT under load, and compare those values to what the manufacturer requires, if you don't see any welded up bungs on your exhaust, they didn't check it, and just assumed.

 

Take your old cat to a scrapyard yoruself (not a junkyard) they are DAMN valuable (I got $175 for an old truck catalytic converter) yours would fetch anywhere from $50 to $75 ... but if you gut it like Turby did, then they are worthless.

 

--Dave.

[3pt1lumina]

Now that you've pulled the cat, is the car throwing any SES codes indicating the cat isnt there?

[birdman]

well i didnt know about the whole scrapyard thing, thanks for the info, and i may just check the front bank to see whats up. and i havent had the ses light come on, i think it only does that on OBD2 cars with 2 o2 sensors.

[turby]

but if you gut it like Turby did, then they are worthless.

 

--Dave.

 

Mine has to be in place for inspection. They don't check to see if it works, just that it's there.

[DaveFromColorado]

but if you gut it like Turby did, then they are worthless.

 

--Dave.

 

Mine has to be in place for inspection. They don't check to see if it works, just that it's there.

 

That's what I figured, which is why I didn't comment 'bout it in your thread. I've gutted my fair share of cats in the past too, just to keep the look of it there.

 

a recent trick that I've learned, is to get a length of pipe that can go into the cat itself, to help get rid of the turblance built up in there from the exahust reflecting off the back side of the cat - it's worth 1 - 5 hp to the wheels on the dyno (depending on other mods)

[Hairdo12]

Now that you've pulled the cat, is the car throwing any SES codes indicating the cat isnt there?

 

Not on an obd1 car... there is only 1 o2 sensor and that is before the cat.

[jeremy]

how raspy does it sound now?

[chadz34]

how raspy does it sound now?

It's probably off the hook.

[birdman]

o yea, tons of rasp but i think my fix has a slight leak so when i get that wrapped up ill know for sure.

[chadz34]

o yea, tons of rasp but i think my fix has a slight leak so when i get that wrapped up ill know for sure.

I wish my 96' DOHC had rasp.

[birdman]

why would you want rasp? i hate it. trade ya