Catalytic converter question 94 Jeep 4.0

Failing HC and CO means the fuel mixture is too rich.
You may need a 4 gas analyzer to figure out why to know when it is fixed. Could be a leaking injector, restricted air intake, ignition problem, or a long list of other things. Even a faulty thermostat could cause it to run rich.

Check out the EVAP system to see if you have a broken charcoal canister or cracked vacuum line. Also check for vacuum leaks.. Those would cause hesitation, stalling. Read this post on EVAP
Chrysler EVAP System Ricks Free Auto Repair Advice

u only did part of the job most people change the air intake first put in a cool box or k&n type which causes some of same problems as opening the exhaust-- ur letting to much air out no back pressure and not enough air going in causing an imbalance also ur going to have problems with o2 sensors/cat sensors also mass air flow down the line

If it has flanges on both ends, just unbolt it and replace. If it has welded pipes you will need to cut it off and use adapter sleeves and clamps. Really not rocket science...at worst, you may need to remove the hangars on the rear portion of the system to get enough room to install.

if the converter is rattlin then it needs to be replaced because the element inside is broken. if the jeep still does not run try removing the catalytic converter to see if the restriction is too much. should start if the converter is restricted. if it doesnt maybe its whatever caused the converter to go bad in the first place

HI, this guide will help you with this replacement.

Step1 Lift your jeep. Unfortunately, the catalytic converter sits about midway down the length of your jeep, so lifting one end or the other will not do. Ramps are your best bet to get you within reach of the parts when working from home. Luckily, this is usually the hardest part of this repair. Step2 Be patient with the bolts, as they are often hard to remove due to size and awkward placement. You may have to drill or saw bolts to remove them. With this in mind, you should pick up new bolts, nuts and seals for your replacement project. Step3 Buy a catalytic converter specific to your jeep to avoid extra work. A generic part must be welded into the jeep, while a vehicle-specific model comes pre-welded to the proper pipes for easy bolt-on installation. Step4 Remove the 02 sensor (with an O2 wrench) before unbolting the catalytic converter. Then, you should remove the pipe connecting the sensor to the converter. Depending on your exhaust system, you may have to remove more pipes before you unbolt the converter from the muffler. Step5 Replace the old catalytic converter with a new one. This should be the easy part, as you simply bolt the new part in place. Step6 Reattach the exhaust pipes and 02 sensor, and the basic job is done. Make sure you replace any cracked or rusty pipes while you have the exhaust system apart.

• Catalytic converters often fall under a separate emissions warranty that lasts at least 7 years and 160,000 miles. Even if your car is out of its regular warranty, but it is a newer model, ask your dealer to replace the part for you free of charge.
• Rent the O2 wrench or socket if you do not own one. Most auto parts stores carry this tool for rentals.
• In many states, older (vintage) cars do not need a catalytic converter, so you can gut it or remove it completely. No damage will result from running a car without a converter.
• Due to emissions standards, it is illegal to buy or install used converters.

Please rate and god bless:)

you don't have to remove any hangors, but some times its easier. After getting it all off, it goes back on the same way. I prefer welding the pipes shut, but its not neccessary, just make sure the U Clamps you are using are good ones and tightened good.

tepfy

On most, you need to remove all bolts around the perimeter of the pan, (You may want to remove starter to get to fasteners there) then slide a paint scraper between the pan and block to break the seal. Generally there is enough room to get the pan out. If you need a bit more room, support the transmission with a jack (use a piece of plywood on top to avoid bending anything) remove both engine mount through bolts and raise engine slightly (not too much or you will break something)

I had a similiar problem it turned out be the catalytic converter. I believe there was a recall for this problem.

Hi

This could be a blocked exhaust. Unscrew and remove the upstream O2 sensor (the one BEFORE the catalytic convertor) and then drive the jeep and see if the problem is resolved. If so then you have a blocked exhaust, probably caused by an internally collapsed catalytic convertor.

It could be a fuel pressure issue which is diagnosed via a fuel pressure test. You could, as a long shot, fit a new fuel filter and see if that resolves the issue, however, a worn fuel pump could also be causing it.

It could also, if the problem only occurs once the jeep has warmed up, be a problem with the upstream O2 sensor.

Very best regards

Geordie