My girlfriend drives a 2001 Nissan Sentra 1.8. For a while the car has sputtered every once in a while and bogs out. then all of the sudden it will be fine. Lately its been getting worse. The other day it was 100 degrees outside and the car was cutting off at stoplights and smelled like rotten eggs. Then the weather cooled down and went to the old routine. now it cuts off all the time idle drops low and if it doesn't come back up to do it again it cuts off... I think the cat may be stopped up. SHOULD I GUT IT? MAYBE THE BACKPRESSURE IS CAUSING THIS I DONT KNOW. Once i gut it will the car sound like ****?


THANKS

 

up

 

wrong section.

 

PHDTS.

 

??


this is the only other make vehicle thread i found

 

if you pull the cat you should be able to determine if it is clogged. It will be obvious. if it is, then gut it, otherwise she has different problems. It won't sound good, but it won't be an obvious noise bomb.

 

yeah pulling that bastard off is harder then i expected. end stripped off and hack saw wont go threw it. I guess the next thing is to torch the bolts...

 

It is highly unlikely your cat is causing this problem. Why are you going in that direction? Try the obvious stuff first like secondary ignition parts.

 

looked up rotten egg smell and it said likely bad cat converter. what else should i look at? o2 sensors etc? there is four of those anyway to find out if they are bad and which one(s). what else to look for?

 

Looked it up where? Rotten egg smell is not caused by a bad catalytic converter. A rich mixture passing through a good catalytic converter will make a rotten egg smell. I would suggest you take it to a professional mechanic for diagnosis or you're going to end up spending a lot of money on parts you don't need. If you gut your catalytic converter your check engine light is going to come on.

 

already have a cel said 02 sensors but they weren't that old. guy told me it was cat so i googled it.

 

if you smell rotten eggs that means its working overtime. sounds like you have a misfire or its running too rich.

 

will check the o2 sensors then

 

Because you have an O2 sensor code does not mean you necessarily have a faulty O2 sensor. An engine misfire, which is what it sounds like you have, will 'fool' the O2 sensor and could trigger the code. Have you replaced the spark plugs, wires, and cap and rotor?

 

Probably COP

 

Hydrogen sulfide in the exhaust, which is produced by trace amounts of sulfur in gasoline. It's supposed to be converted to sulfur dioxide in your catalytic converter. This may be indicative of a fuel-injection problem, and can be cured by a sharp mechanic. But often it means a failed catalytic converter. The bad news: A new cat is expensive. so there you go that's your problem

 

That may be true, I didn't look it up. But remember Coil On Plug still has a rubber boot which runs from the coil to the plug and they do leak sometimes.

 

mass air flow sensor

 

this really sounds like you should take it to a trusted mechanic that REALLY knows how to diag. Clogged cats are rare. If you gut it the smell will go away but it will not fix the problem. The CELs and smell sound like symptoms, not problems. If you dont have the proper tools or the knowledge to isolate the issue then just suck it up and pay the $90 diag fee, then fix the issues yourself. Make sure the shop will offer you a warranty or guarentee of some sort if their solution doesnt fix the problem. If they wont then they are not the shop to use.

 

change the cat and clean your injectors see if that works

 

That would be a waste of money.

 

OMFG dude fix the root cause of your o2 code (its misreading a lean a/f and over compensating look at your fuel trims!!!!!) and your problem will be solved. It's obviously running insanely rich hence the hesitation, low idle and stalling. By now your cat is probably done(sulfur smell). I love people like you, make my bank account happy.