clogged cat??? - Toyota Nation Forum : Toyota Car and Truck Forums

nova-rolla · 10-12-2006, 10:37 PM

every morning and on days when the car sits for more than 3+ hours, when i start the car up is sounds kinda lumpy. when i start to accelorate it seems hesitant until i get it warmed up and then it runs good with no hesitation. clogged cat?
i replaced the following
plugs
wires
cap and rotor
fuel filter
o2 sensor

any ideas and what to check?

TheOtherCarolla · 10-12-2006, 10:41 PM

Sounds like a smog device like an egr valve, but yes, a clogged cat can simulate the same problems. When the car is cold, go smack you catalytic converter, if it sounds like popcorn bouncing, you found your culprit.

nova-rolla · 10-13-2006, 10:32 PM

cool, thanks i will have to wack it in the morning

nova-rolla · 10-14-2006, 07:38 PM

well i tapped on the cat and sounds ok, maybe its the egr valve??

Bitter · 10-14-2006, 09:13 PM

a clogged cat can make no sounds. when you try to accelerate hard does it just feel flat like the engine isnt able to breath? best test is to measure the temp of the exhaust pipe before and after the cat. it should be hotter after the cat, if its hot before the cat and cooler after then the cat is probably clogged. or you could just unbolt the cat and if you cant shine a light through then its no good.

nova-rolla · 10-14-2006, 10:00 PM

about 2 months ago i was having all kinds of excess blowby and oil was just seepin into the carb and down that flap which goes into the exhaust manifold and causing some serious smokage on the highway so i made a homemade catch can and that relieved the problem with the oil and smoke. so today i replaced the spark plugs (i replaced them 4 months ago when purchased the car). they seem to have a crap load of oil gunk on them.i was wondering what kind of ill effects all the oil goin into the carb/ and manifold would have. such as cloggin the cat or fouling out the new 02 sensor in the manifold. can that sensor be cleaned out?? i like the fact this car for the most part seems easy to work on and plenty of room in the engine bay.

Bitter · 10-15-2006, 12:38 AM

yea, all that oil can be detremental to the cat for sure.

nova-rolla · 10-15-2006, 10:18 PM

semi clogged cat cause hesitation on a car thats been sitting for hours? only happend in the morning before work and when im leaving to come home. like i said only for a few min then seems to run better..

Bitter · 10-15-2006, 11:02 PM

hmm...happens only when the engine is cold?

nova-rolla · 10-17-2006, 09:07 PM

cold meaning sitting for more than 4 hours. if i start it up after i have been running it, it wont hesitate.

Bitter · 10-18-2006, 01:56 AM

well that doesnt sound like a clogged cat issue. im not very familiar with your year, but is the choke working correctly?

also, is the pipe to your intake from the exhaust manifold still hooked up? it needs that to run correctly when the engine is cool, the hot air helps to atomize the fuel in a cold engine and it'll run poopy without it in cold weather.

nova-rolla · 10-18-2006, 08:48 PM

which pipe, the one that looks like dryer vent hose??

Bitter · 10-18-2006, 08:58 PM

Quote:

Originally Posted by nova-rolla

which pipe, the one that looks like dryer vent hose??

yes, it should go from the exhaust manifold to the intake somewhere and be about an inch around and look like dryer duct.

diver9000 · 10-18-2006, 09:22 PM

Quote:

Originally Posted by Bitter

also, is the pipe to your intake from the exhaust manifold still hooked up? it needs that to run correctly when the engine is cool, the hot air helps to atomize the fuel in a cold engine and it'll run poopy without it in cold weather.

POOPY? what kind of word is poopy....

Bitter is right for sure about that manifold pipe.