well all the sudden for the past week my car has been ideling really really really really ruff when i'm stopped, in park drive or what, the rpms get down to the notch before the last one and the car shakes really bad, but it does it in pulses , thats the only way i know how to explain it, it will get really bad then ease up then again really bad, and yesterday driving home my check engine light came on, any ideas? its a 98 4cy auto, just under 98k on it

 

well my cel is this, 67: Catalyst System Efficiency Below Threshold but what is that? lol

 

Usually obvious when idle rpms fluctuate. If it is dry outside or after 15 to 20 minute works fine, then damp conditions give problems then it could be the wires by themselves.

Good Luck

 

lol what?

 

It means your cat is pretty much shot. Based on your mileage, it sounds about right. If the honda scan tool was hooked up, it would read "catalyst deterioration". Time to replace the cat.

 

im gonna help u my friend, i pmed u also on honduh, anyway, i have had the SAME EXACT CODe for 2+ years. i will save u some TIME AND MONEY. i have dumped already soOoo much time going from so many friends houses who know a lot about cars, guys who have done engine swaps, actual honda dealer service technicians(friend works at fairfax honda), and jweller, im sure u seen him around the boards(here, honduh, honda-tech, etc), one of the smartest dudes i kno who knows his stuff about our hondas. it can be only 3 things, most likely 1 of the 3 things, maybe 2 at most, never all 3. its catalytic converter below threshold efficiency something, meaning the primary o2 sensor is bad(header o2), the secondary o2 on the catalytic converter(cat o2), or the cat is actually bad. now, if ur below 88K miles(i believe this is the extended emissions warranty, maybe 80K), honda HAS to replace ur cat, the extended warranty includes the cat, o2s are not covered under the extended emissions warranty. now if u have aftermarket parts, they may not actually do the service for free. i kno the honda who sold my car, they did some services for me, like couple oil changes, and 60K tuneup, they turned me away(bastardS!), cuz of my catback exhaust and CAI, and being lowered they said, i may have hit the cat on the ground. but u can try out different honda dealers, see what happens. if ur over 88K my friend, ur out of luck. most people say o2 sensors normally go bad first b4 a catalytic converter, but my problem is the cat i think. i had a crack on the downpipe of my OEM header, so som1 told me, the CEL could be from the additional air getting into the my header that is messing up the o2 sensors reading, so i got a new downpipe, CEL stayed on. changed the o2 on the header, CEL STILL stayed on(btw some people have experienced problems with universal aftermarket o2 sensors, they run rough afterwards even if it solved the problem, i do run rough after changing mines, later found out he changed it with an aftermarket one, the o2 on the header helps with the air fuel thing, makes me think u have that problem, i kno several with code 67 and they changed the o2 on the header and solved the problem, lucky bastards, the o2 on the cat is basically a nanny for the emissions thing, doesnt really involve the performance of ur car like the header o2). i used to be slammed 4 inches to the ground, so perhaps i smacked around the cat, so i just bought a cat, and if it doesnt work, its the o2 on the cat i suspect, but i think its my cats thats bad. and taking out ur cat and shaking it, and lookin inside doesnt do anything. i had 2 people take out my cat, its white and clear inside, normally meaning its good, gently shook it to see if anything is broken inside, nothing... it looked perfect, i could see through the other side inside the cat. i actually bought a used cat awhile ago, and SOLD it, DAMN IT cuz people said my cat wasnt the problem! friend who works at honda recently said, just do the cat, my car feels like at 80 mph, its kinda bogged down, cant accelerate, and my gas mileage sucks, ur car will NOT get better, at idle my car runs rough sometimes just like your symptoms. CEL light goes on and off, but it will come back. i did, spark plug change to denso iridiums ik16(one of the most expensive), changed my cap and rotor, fuel injection service, radiator/coolant flush, all this other bullshi* trying to get rid of the CEL, just a waste of money

 

check out this thread, the guy on it is very knowledgable, he helped me find out what the possible problem could be for my code 67

https://www.honda-acura.net/forums/s...d.php?t=169032

i hope u fix ur problem quick. i didnt really try to fix it until last year, when it didnt get fixed after dumping couple hundred i waited again till this year, now i am sick of the poor gas mileage, and rough ride im just going all out

 

well i have a magnaflow catback, and its just over a year old so it shouldnt be the cat right?

 

huhhhhh lol

 

is there anyway to know which o2 sensor it is without taking it to honda?