Topic: Catylitic convertor question??

[SMC4WD]

These are my three steps to passing emissions...

#1, change the cat
#2, change the oil
#3, locate and possibly disconnect the charcoal cannister for the fuel vapors.  Rumor has it that it too could be causing a problem.  Definately last thing on the list.

I really need it to be registered...  I drove it around all day Saturday, and it could have been a $150.00 play day.

[Mozman68]

hah.."passing emissions"...

One thing I love about living in Michigan...no inspection...you can drive around with no doors and no hood on the car if you want.

Surprisingly, not as many beater type cars driving around as you'd think.

[YJmechanic]

pa is pretty easy, inspection is all safety and emissions is simple.  95- all equip must be there and 96+ no engine light on.

[SMC4WD]

pa is pretty easy, inspection is all safety and emissions is simple.  95- all equip must be there and 96+ no engine light on.

But do they do the sniffer test?  Testing CO and O2 at idle and at 2500+/- RPM...  I've failed 3 times already at idle...   :cry:

[YJmechanic]

depends what region you are in.    i forgot to mention that.  where i live, no they just visually inspect the equipment to check and make sure it is there and hooked up.  they region around philly and pittsburg have the asm testing but even they are eliminating them.  they are going to the simpler system that we have.  i know cause they told me when i got my license renewed and they said you no longer need the additional certifications.

[tttppp54]

Would a semptom of a clogged cat be a rough start. When i start my engine it stumbles, almost cuts off. Let it warm up a little and it is fine. Also, there is a vibration right b4 2k rpms under the floor board where the cat is. Once above 2k its gone, any ideas?

[YJmechanic]

well the converter can rattle when the catalyst breaks down but they generally cause more problems when hot then cold.  just bang on the converter and see if it rattles.

[SGT_Tirrell]

I would just straight pipe it, as I know you can get some money out of the old Cats because they have platinum in them.  I think my dad turns them in to a recycling place for like 25-30 a piece.

[Jeepin' Texan]

Will a bad cat cause this?:

I will be driving and it will start to like back fire and like it is not getting gas. I have change all of the following: plugs, rotors, cap, wires, 02 sensor, fuel filter, throttle body and TPS. But it still does it. It doesn't do it all the time, it just comes and goes when it wants. I am willing to try just about anything else. How can you tell if the fuel pump is going out? How about the fuel injectors? I am thinking it has something to do with fuel. When it does this the engine never dies it is just like it is starving for fuel. I can keep punching on the gas pedal and it doesn't rev it just feel like it is starving for fuel and backfiring. Any and all help is appreciated.

I have installed a new cat about 4 months ago. Is it possible to install it backwards?

[Guardian7]

Sounds like it could be the cat, if the cat stops working it will not burn off the extra fuel vapors which might cause the backfire and when the cat cloggs up it really kills your power too.

[Tall Boy]

If it comes and goes when it wants, I would assume it is an electrical problemo there. Or a blockage of the fuel intermittently like say when it sloshes. A cat will kill the motor when hot and foul when hot, specifically.  I would not just keep throwing parts at it though,youve already spent mass amounts of dough as it is and still not located it. The dealer can put it on a scanner. It will throw a check engine light if it causes a problem with the operational systems,and the dealer can tell you why.  Is your battery good to go, Is it getting 12v? Got crud on the terminals? how bout overheating? Tell us more Texan!
 Remember the Alamo !

[Jeepin' Texan]

OK, here we go. IT never heats up, always around 205-210. I put my hand up against the tail pipe and plenty of pressure coming out. I am getting ready to test the fuel system. I have a friend who has a tester. The engine never dies it is just like it is starving for fuel. When this happens i turn the engine off for about a niute and then she runs fine. So i don't think it is the cat since it is brand new. Does it matter which is the inlet and which is outlet on the cat?

[Tall Boy]

I am not positive but I would guess it only goes one way. It is a honeycomb deal. It also depends, it should throw a light on if it is running bad.
 Intermittent problems are ususually not mechanical, but moreso rubber gaskets, electrical wiring, the battrey, something shaking loose with idleing. clogged fuel filter in tank.
 what kind of a Jeep is it? what year? how often is it happening? how long has it been going on.

Does the fuel pump make any noise?

[Jeepin' Texan]

It is a 1995 YJ w/4 angry squirels. I bought it used in May of this year. when i bought it and drove it from SC it never did this. Well a few months later i had the tranny rebuilt and the exhaust put on. All it had before was a glasspack (talk about loud). Since the tranny rebuild and new exhaust it has been happening. It doesn't happen all the time just whenever it feels like it. Like i said the engine never dies just like it is starving for fuel. Once i turn off for a mnute she will run fine. I have never gotten any codes when this happens. I am at a total loss her.

The fuel pressure test was ok. 41psi with the vacuum line disconnected and 32 when i connect it back to the regulator.

[Jeepin' Texan]

The fuel pump makes no noise.