HELP! clogged cat??

[wrangerdang]

hi guys need some ideas before i start throwing money at this problem.

replaced my dizzy, rotor and leads couple of weeks ago to get rid of a stuttering problem. also cleaned out throttle body. got rid of stuttering problem but exhaust note is terrible.

when decelerating in gear it sounds like the cat is backfiring and gurgling something terrible. can feel vibration under driver foot. when accelerating no problem but does sound a little "beefier"

been like that for a week - was hoping the carbon buildup might blow out but last night tj lost all power and spluttered and was shaking violently when putting pedal down. was idling terribly as well. pulled over and threw code 21 which is o2 sensor. left it overnight and started to go okay this morning - noisy but went about 10 minutes before same problem started again.

does this sound like a blocked cat? i would imagine a blocked cat would throw out an o2 sensor and prob damage it at the same time?

finally, do RAC call out vans have a sensor to detect exhaust emissions and whether a cat is stuffed? currently have heep parked out the front of my nans as couldnt make it to work this morning.

its a 97 5 speed. sorry bout the long post! all ideas appreciated!

[Laz]

a stuffed cat - I had this issue - the muffler shop used one of those IR laser (I like lasers..) temperature sensors after taking the car for a short hard run, the front of the cat was 30% or so hotter which means its shagged - the back of the cat is meant to run hotter as burning any of the unburnt hydrocarbons in the cat is exothermic (reales heat)

Once the cat was chnaged I went from 22 L/100 round town back to 16-17L/100

Any muffler shop should be able to test for you mate.

Originally Posted by wrangerdang

hi guys need some ideas before i start throwing money at this problem.

replaced my dizzy, rotor and leads couple of weeks ago to get rid of a stuttering problem. also cleaned out throttle body. got rid of stuttering problem but exhaust note is terrible.

when decelerating in gear it sounds like the cat is backfiring and gurgling something terrible. can feel vibration under driver foot. when accelerating no problem but does sound a little "beefier"

been like that for a week - was hoping the carbon buildup might blow out but last night tj lost all power and spluttered and was shaking violently when putting pedal down. was idling terribly as well. pulled over and threw code 21 which is o2 sensor. left it overnight and started to go okay this morning - noisy but went about 10 minutes before same problem started again.

does this sound like a blocked cat? i would imagine a blocked cat would throw out an o2 sensor and prob damage it at the same time?

finally, do RAC call out vans have a sensor to detect exhaust emissions and whether a cat is stuffed? currently have heep parked out the front of my nans as couldnt make it to work this morning.

its a 97 5 speed. sorry bout the long post! all ideas appreciated!

[PK]

I DIDN'T have a rattly cat in my TJ, I DIDN"T pull the tailpipe off and break up the insides of the cat and empty it out, and if I had've IT WOULDN'T HAVE made it sound or run better.

[ShadoZJ]

Originally Posted by PK

I DIDN'T have a rattly cat in my TJ, I DIDN"T pull the tailpipe off and break up the insides of the cat and empty it out, and if I had've IT WOULDN'T HAVE made it sound or run better.

GOLD!!....

[wrangerdang]

Originally Posted by PK

I DIDN'T have a rattly cat in my TJ, I DIDN"T pull the tailpipe off and break up the insides of the cat and empty it out, and if I had've IT WOULDN'T HAVE made it sound or run better.

okay, well i definately WON'T be doing that then!

[starter]

what makes you think its the cat? and if it's blocked, what with?thats a lot of carbon deposits falling of valves to block a cat. if that were so you engine would be lacking compression as the valve seats would be shagged.
there are many things that it may or may not be, if you are not sure, get some one to check it out and show/explain the problem to you. saves spending coin were it isn't needed

[ShadoZJ]

http://autorepair.about.com/cs/gener...a080401a_3.htm