solaris_vii

iTrader: (3)

i have an 85 iroc with a tpi that has been having some problems as of late that keep getting worse, and im starting to think maybe a clogged cat is to blame. sometimes, doesnt matter if its start up or if ive been driving awhile, speed doesnt matter, rpm doesnt matter, but sometimes the rpm will just drop to maybe 400 bouncing from 0 to 400. ill pull over, and just keep revving it until it will idle again, could take a second or maybe a couple minutes, and when i do a huge cloud of smoke comes out the end. it used to have a problem when going highway speeds, when you stepped on the gas the rpm would drop while your foot was on the gas and then when you let off the gas they would increase, i ignored that problem and maybe i shouldnt have because no even going to work is a chore.

i guess my question is, could a clogged cat be causing part or maybe all of this? and what kind of symptoms are common with a clogged cat? ive recently changed the air filters and spark plugs and spark plug wire, so i know its getting air and spark, and the fuel pressure is fine so i know its getting fuel, my only gas then is air is coming in but never getting out. any help would be greatly appreciated.

Jproz1167

iTrader: (3)

dont sound like a clogged cat.

Texan25

A clogged cat in my experience (1998 GMC Jimmy, 4.3L V6) came with over heating (but cept cool enough with the heater on), a very, very anemic motor that would struggle up hills, and the transmission was acting very funny from the engine's lack of power too, which led us to initially thing it was the tranny.

ryan91rs

iTrader: (1)

if you are throwing smoke clouds when you rev it, i don't think it's you cat. The sign of a bad cat is that sulfur smell or a lack of power and a shut down b/c too much back pressure and/or overheating. sounds like you might have a valve train problem.

TA

iTrader: (1)

Sounds like it's running rich. Is the "Check engine" light on? Check your trouble codes. I had a similar problem and it was just a crusty connection at the connector to the temp sensor (just below the throttle body), making the computer think the car was ICE COLD, and dumping fuel into it (like a choke). Cleaned the connector and it ran like a champ.

Good luck

TA

blackphoenix

Hello. I had a car with a clogged cat & the transmission would act up when it got hot, going up hills, & it would overheat. Take your car on a nice ride up some hills late at night, go where it is dark and if your cat is bad it will look like the element of an electric oven. We did so much work to the car we had never thought it was the cat until there was not much left, went on a nice ride up the mountains pulled it over & was surprised at the glowing cherry red dual cats. What color is the smoke its blowing & how does it smell? The list could be endless for what is wrong with your car but here are some things I would check for a loping idle:
Any vacuum leaks including Intake Manifold or fuel injection unit, Leaking EGR valve, clogged PCV valve, leaking headgasket, worn timing chain/ or gears, bad cam lobes, MAF sensor,idle air control. Been working on 3rd Gens for years and it could be alot of different things or a combination of a few things. If you do it yourself I would check the MAF sensor & vacuum lines first. If not the best thing may be to get a diagnostic. In PA with an hour of labor they run about $60,
Good luck. Shenna

ryan91rs

iTrader: (1)

so did you find out if it was clogged?

blackphoenix

DId you check the cat yet? Everything all good?

Jproz1167

iTrader: (3)

when I had my first and only cat plug it was on my 84 trans am at about 24,000 miles ... what did it act like .... simple couldn't get over 25mph by the time I got it to a dealership. and yes it got way hotter then normal on the way to the dealership. It was in the daytime so can't tell you if the cat was glowing but I'm certain it was lol.

solaris_vii

iTrader: (3)

sorry it took me so long to respond, i just moved and we dont have internet yet. the car eventually stalled and wouldnt restart so i had to have it towed to a shop (and they scraped my front bumper when they towed it!) and it turns out the car had a malfunctioning ignition control module. sometimes it wouldnt send a spark at all leading to the rich condition and as a side effect the cat went bad. i knew for sure the cat was bad when i got it back because the car was suddenly quiet (i have a flowmaster muffler) reaked of exhaust in the cabin and overheated. so i changed that, car runs better than ever, feels stronger, and is louder than it ever was. love it. thanks to all the help you guys sent, couldnt have done it without your help

1991ON20's

it amazing what u find on the boards..........my ride is sluggish going up hills....and it does run rich.....i wonder if i have the clogged cat or busted tranny problem.

solaris_vii

iTrader: (3)

the biggest tip to a clogged cat is does your car get up to temp REAL quick? when mine was bad it would be up around 200 degrees after maybe ten minutes. also, i had my tranny go bad once (im assuming youve got a 700r4) and what happened to me was it wouldnt shift out of first until 4500 rpm, out of second until maybe 3000, and i was lucky if it would want to shift past that. id say if your car is only giving you troubles on a hill, the tranny isnt your problem but you never know

shawn21

I have a 1996 z28 camaro and something just happened recently when I put it in gear it barely wants to move forward at all now reverse isn't working. When it first started happening the rpm would bounce from 0 to about 2000 and kept doing it now there's a weird sound underneath the car around the transmission I don't if the catalytic converter is clogged or if it's the torque converter could someone help me out with this...thanks

fireburdluvr85

What you just described is a bad torque converter. Atleast in my experience.

That's your description shawn21

shawn21

Thanks. That's what I thought it was.

Reid Fleming

iTrader: (2)

Easy way to check for a clogged exhaust is with a vacuum gauge.

middian

im getting this on a cold start. Fuel pump working properly, filter replaced, ignition module and coil replaced about a year ago. Could it have gone bad already?