grey90xj

iv replaced a lot of cats in my day that statement is bullcrap..thats why u can go to the parts store buy one right right this form sometimes makes me laugh

Firestorm500

Rules for Replacing Converters
In 1986, the U.S. Environmental Protection Agency issued new guidelines for the construction, efficiency and installation of aftermarket catalytic converters. All CleanAir converters listed in this catalog have been designed, tested and manufactured to meet this policy.

In addition, CleanAir converter listed in this catalog is appropriate for use under the current requirements of the California Air Resources Board (C.A.R.B.).
E.P.A. guidelines state that replacement converters may be installed only in the following situations:

1. The vehicle is missing a converter
2. A state or local inspection program has determined that the existing converter needs replacement
3. Vehicles manufactured prior to 1996 must have more than 50,000 miles, and a legitimate need for replacement must be established and documented
4. In cases of OBD Il-equipped vehicles (1996 and later), the O.E. manufacturer's 8-year/80,000-mile warranty must have expired and a legitimate need for replacement must be established and documented.
Please note that Federal law prohibits removal or replacement of a properly functioning O.E. converter.

When replacement of the converter is appropriate (as outlined above), the E.P.A. further requires that:

1. It be installed in the same location as the original
2. It be the same type as the original (i.e., two-way, three-way, three-way plus air/three-way plus oxidation)
3. It be the proper model for the vehicle application as determined and specified by the manufacturer
4. It be properly connected to any existing air injection components on the vehicle
5. It be installed with any other required converter for a particular application
6. It be accompanied by a warranty information card to be completed by the installer.

Here's your bullcrap right back atcha, dude. I never said you can't buy one at the parts store. I have done that. But it's not the same as replacing a windshield wiper.

grey90xj

i knew you would post some big explanation on this haha at the same time fix your pocket protector

Firestorm500

I see you fixed your post.

You don't know anything about me at all.

grey90xj

and i dont cair too

DFlintstone

Probably not. If it were not seating it would be a problem at idle. Having it always being seated, (IE, the vacuum to it's diaphragm never makes it pull out), should always be fine. If it were active it would provide Exhaust Gas Resurlation to your intake manifold. For trouble-shooting, make sure that diaphragm's port NEVER has vacuum.

Anticreep, this is a pretty good forum with people that can help you. I generally ignore posts that are not concerned with the OP's problem, being OEM Jeeps from 87 to 2001. Talking to people off topic, just encourages them. OEM Cherokee Teck, is a teck forum, specifically about Jeeps.

I had a booger of a problem. Similar symptoms as yours. Took me maybe a year to find. Not that I knew where or how to look, but it was one of the wires going to the lower sensors grounding. Turns out it was the heat shield that would expend to make the short, after I had shut it off hot. (see the photo!).

I don't know witch wire was grounding. (I could still check)(I just taped it in 2010). It would "dog" and pop out the intake when I throttled it, but take off fine floor-boarded

Like I said, I'd take 90 seconds to rule out the CPS. (That's just me). Then I'd see that my sensor ground circuit is around an OHM of resistance(or so). (that is checked with all power off).

I'm getting a little stumbling at high temps and hard throttle. Although I just gaped the AC Delco plugs I just put in in 2011, (they seem fine), I'm thinking of some Champion, or NGK, Copper if I can find them.

Point being that as combustion pressure goes up, it takes more voltage for the spark to jump the gap. Yea, funny that. Condensation inside the distributor cap could make an engine misfire under load.

I know my map tube us good. I need to check my CPS....if I can find time...

anticreep

Thanks DFlintstone I'm going to check that tomorrow and check the ESU and all the grounds. I'll let u dwellers know what I find out if I find out anything.

anticreep

I tested my CPS and this is what I got. It says it needs to be between 125 - 275 ohms. It says if it's outta range much to replace it. Do u think the CPS is bad and causing it to loose power.

I'm going out now to test the grounds to see if any are bad.

TwoXJS

It's better to check the CPS on AC voltage while cranking. I believe it's cruiser54 that says "It can read good on ohms, but still be bad on the AC output." The one in my brother's '89 only reads, at the highest I've seen, .28 volts. It will still start and seem to run good, but after even just a few minutes of driving, it runs like crap....

anticreep

TwoXJS
How do I test it while cranking. I unplug the CPS from the wireharness and hook my volt meter up to the plug coming off the wireharness and crank it over??

TwoXJS

Right, but it's a lot easier with a helper. Have them probe the pins in the connector going to the CPS while you crank it for a few seconds. It won't start without it hooked up, so no need to worry, but be mindful of where the multimeter wires are and keep them away from pulleys. Ask my why....Lol

anticreep

TwoXJS.
Just ran that test and it showed 1.0 AC VOLTS.

TwoXJS

Huh....I think you want around .35 to .50 volts. Let's wait a little while and see if anyone more experience with this chimes in. I'm not that great yet with Jeeps since I'm still rather new myself to the world.

anticreep

I just tested the O2 sensor and unplugged it showed 2 ohms and the volts with the motor running and up to normal temp it showed 5.23 V but it stayed there. Do u fellers think it could be the O2 sensor causing my problems.

These are the tests I ran.
Connect the ohmmeter test leads to connector terminals A and B of the sensor connector. Resistance should be between 5 and 7 ohms. Replace the sensor is the ohmmeter displays and infinite reading. I don't know about you, but this test is pretty vague. They say it should be between 5 and 7 ohms, but infinite is bad. What if you get a reading of 13 ohms or 100 for that matter? I wasn't too fond of this test as I found it is a test of the O2 sensor heating element!. One other thing you can do with the O2 sensor is hook up the voltmeter to terminals B and C (I can't remember if those are the right letters, but you want to get the sensor wire (believe it was blue) and the ground wire, or just ground to something else) with the connector hooked up and the engine on, warm, and idling. You should notice the voltage jumping up and down in about 2 second or less intervals. If it doesn't jump up and down considerably or takes longer than 2 seconds to do so, change it.

DFlintstone

Pardon me, I've been busy. I guess Cruiser is ether not interfering or busy himself. .1 ACV directly from the two wires from the CPS means it needs help, or changing out. See cruisers stuff in my signature for how to drill it's holes to bring it closer to the flexplate notches. I've even read of people just smacking it in closer. I recently worked on a Jeep with a .1. It would usually start and run, but die at stoplights, (the old guy said). I doubt he was ever "getting on it" .....Mine died (I mean it would not start as usual, (no, I didn't keep cranking)), soon after it dipped under .35.

I'd put the 02 sensor on the "back burner" for now. You DO have an excellent meter that MAYBE CAN check it. You have the low impedance, but the fluctuating voltage may come out gibberish on a digital. I'm curious if the book on it mentions a "sampling rate". In the top of this post is a link to EcoMikes info on testing Renix 02's. https://www.cherokeeforum.com/f2/ren...ce-rms-133153/ I "put off" cleaning my grounds at the dipstick tube until I was checking my 02 sensor. Picked up 1/10 th of an ohm when I cleaned it. See cruisers#5, sensor ground check. It would be easier to just check from the map sensor, but going from the TPS also tests suspect crimp connections in the wiring harness.

Btw what I, "forgot" in post #14 was the vacuum test for a clogged exhaust. A mute point if your ECU is not sure where your crankshaft is!

So.. here is my "Long version"

CPS
AC voltage CPS test; Small clips on the meter leads really helps.


Unplug the connector at the back of the manifold with wires going down to the bell-housing/cps.
Probe the two wires to the cps with the meter set on AC volts. (a 200 scale on mine).
Crank the engine and note the voltage. (jump it if your battery is low)


Mine somehow works with only .3 my wiring/grounds must be pretty spiffy. .5 seems to be a good mark. One article talked of .5 to .8. Edit, mind died soon after that.


If it's low you can modify the cps. With the next largest bit that won't fit in the hole, enlarge the hole just a tad. Now when mounting it's crucial to maintain firm downward pressure on it while tightening the bolts. An assistant could help with that from above.




Change a CPS. A jack-stand under the left frame might be in your way. BACKING the front's onto a ramps is an option. Sometimes when I lift a vehicle, I see if I can push it off it's “lift” before I go underneath. You lay on your back with your feet out under the passenger side. With your LEFT hand you can reach up past the front drive-line to hold the CPS. (if your forearm is smaller than a quart mason jar)(if not maybe pull the front drive-line). You want 11mm. or 7/16 socket, to 3 inch extension, to swivel,> then 18 to 24 inches of extension to your 3/8 ratchet in your RIGHT hand down by the tranny cross member. If there is a plastic deal there, can it. DON'T drop a bolt in there! (just don't!!!). When you are starting out, if you tie a long string, 5ive feet, to the old plug, you can then use that to haul the new one back up.
If your wires go through a metal band secured by an engine to bell housing bolt, cut them. To finish, zip tie, or make darn sure the wires won't rub/chafe or burn on anything. The second one is a relative piece of cake! (½ hr job!).



Echlin # CSS980 from Napa or one from the dealer, (Mopar) are really your only two reliable options.


Make sure you are on your lowest AC scale, and it's under .35- .4 ish, cranking normal. If that is indeed the case, it needs help. You need that heartbeat, and good grounds for the sensors before you can move on to work on anything else. That AC test for the CPS is independent/separate from the sensor and ECU grounds. I think it's a transducer that would make a square wave on a scope. Anyway nothing needs to be grounded to test it...well the starter!