Check Engine light

Tom-D said:
2007 Jeep Wrangler 3.8l-V6 coming out of Seattle in heavy stop and go traffic I get a light. I stopped checked all fluids under the hood, nothing seemed wrong, not over heated, oil full on the dip stick. So, I drove it home and it seemed to run fine.
today I pull the codes PO-430, is the catalytic converters under the manufacturers recommended efficiency code.
I reset the light and drove the jeep around doing errands and the light stays out.
Question is: would you change the converters now (1200 bucks) or wait until the light keeps coming on and won't stay out
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I had the same with a Subaru. Dealer service guy was up front about what it was and didn't push it to sell a new one to me. I had them do some regular scheduled type tune up stuff. It went away.
 
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If no exhaust leaks are found and sensors are in working order have one of those 3 step fuel system cleans done to it. The type where they hook the hose up to the intake manifold and let the cleaner drip in. Doesn't really do much for cleaning fuel system but it gets the converters really hot and cleans them out. We try it on most cars that set a 420 code and it nets good results.
 
How many miles are on it and when is spark plug replacement due. I had check engine light on my Ford Escape, (it was running fine) spark plugs fixed it. Never pulled codes.... that was 75k ago.
 
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I
Criitter7 said:
If no exhaust leaks are found and sensors are in working order have one of those 3 step fuel system cleans done to it. The type where they hook the hose up to the intake manifold and let the cleaner drip in. Doesn't really do much for cleaning fuel system but it gets the converters really hot and cleans them out. We try it on most cars that set a 420 code and it nets good results.
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'

I've done something similar by finding a manifold vacuum hose fitting somewhere close to the center of the intake manifold. Disconnect the hose, plug it, find another piece of hose, connect one end to the fitting and drop the other end in a can of Sea Foam, letting the manifold vacuum draw it out into the engine intake. Cleaned up an old Chevy truck one time enough to get it through emissions. It does heat up he cat quite a bit.
 
Tom-D said:
nothing listed for jeep
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When your cat looses oxygen storage sites (probably due to the oil you are burning - it doesn't take much over time) the rear sensor starts to switch faster / more often. An RC filter will slow it down no matter what brand of vehicle you are driving. Now, I am not familiar with the exact algorithms use by Chrysler, but the physics are the same no matter what the brand is. And, if the light gets troublesome, a couple bucks worth of parts are worth a try.
 
PaulS said:
Look for a leak or hole in the pipe. OBD cycles the converter to make sure it's there, this was done mostly to thwart those who cut out the converter or put dummies in for the O2 sensors. Also manifold leaks could cause an issue like this. I'll tell you I had an issue with my Hemi Grand Cherokee, a code where the o2 sensors were too slow to respond plus your code occasionally, but mainly the slow to respond code. Mechanic replaced the sensors, no joy. I said to replace the PCV valve, they didn't have one and told me no way that was it. So this went on for about 6 months and about 5 trips. One day I had to get an inspection done, they check them via the OBD here, codes like you have will flunk the car. Anyway I had this inspection coming up. Dealer didn't have the PCV valve, nor did the local auto parts stores, so I found one on Amazon and bought it. Plugged it in and the problem went away. I think the valve wasn't closing properly and was allowing air into the manifold past the flow sensor. Cat converters rarely fail unless the car is running right or the catalyst is damaged and blows out the tail pipe. You can do a temp test to see if the converter is working.
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And this is why you don't tell people to start diagnosis with codes. Except in this case he really has to because the fault is a MIL.

He got a code, and went straight for the part in the title. Maybe it's the problem, but as you say, it's not likely compared to other problems. Exhaust leaks are not rare problems.

Even if the cat were hosed, it would much more likely be a symptom of something else than a primary fault. The replacement would fail, too. Aside from rock hits (not easy on a manifold mounted cat), or intentional damage, there really isn't much that can break in a cat.

The moderate oil use may also be relevant, if it is truly being burned rather than leaked. But I'd doubt it in the absence of a drivability problem.
 
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If the cats ever start rattling, get them out ASAP. Once the ceramic breaks up, it gets blown back into the muffler and usually plugs it up. Then the back pressure blows your exhaust manifold gaskets. DAMHIK :mad:
 
Bill Jennings said:
If the cats ever start rattling, get them out ASAP. Once the ceramic breaks up, it gets blown back into the muffler and usually plugs it up. Then the back pressure blows your exhaust manifold gaskets. DAMHIK :mad:
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... or it breaks up into the second cat, taking it out as well. DAMHIK - 2!!
 
Once you've identified the problem, get the O2 sensor, whatever, through Rockauto.com. Great prices!
 
Bill Jennings said:
If the cats ever start rattling, get them out ASAP. Once the ceramic breaks up, it gets blown back into the muffler and usually plugs it up. Then the back pressure blows your exhaust manifold gaskets. DAMHIK :mad:
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They aren't.
 
Just checked with a friend of mine. His price to replace the Y-pipe and cats is around $800 to 850 without looking at it.
 
This story is fictional (or is it?). Anyhow..I live in a state with no testing.

I just swing by the exhaust shop, hand them $100 in cash, tell them I need no receipt, and ask them to cut the damn thing off and weld a pipe in it's place. Then I just stick a piece of tape over the silly light.
 
MAKG1 said:
And this is why you don't tell people to start diagnosis with codes. Except in this case he really has to because the fault is a MIL.

He got a code, and went straight for the part in the title. Maybe it's the problem, but as you say, it's not likely compared to other problems. Exhaust leaks are not rare problems.

Even if the cat were hosed, it would much more likely be a symptom of something else than a primary fault. The replacement would fail, too. Aside from rock hits (not easy on a manifold mounted cat), or intentional damage, there really isn't much that can break in a cat.

The moderate oil use may also be relevant, if it is truly being burned rather than leaked. But I'd doubt it in the absence of a drivability problem.
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Unfortunately the only symptom was the code in my case, which makes your point invalid. The car ran very well. It's been over a year now, but the only other telling symptom was the rear O2 sensor on one side wasn't acting like the other side. It kind of ticked me off when I was talked out of the solution by the experts, just made sense to me, especially after the integrity of the intake and exhaust manifolds plus the exhaust system were verified.

Cats can be burned up by incorrect mixtures, misfiring cylinders or what ever. But that is pretty rare and usually can be caught by investigating a lousy running engine long before the cat fails.
 
Today while crawling around under the jeep I discover I have a rear main seal leaking. That will require a transmission and transfer case removal. I'm simply not up to that. bummer.. seeing as the "Y" pipe must come down to do the rear seal ?? it will all get completed at one time.
This will be the second time the tranny has been out. :(
 
Well I guess you found out why you are going thru a quart of oil every 2500 miles. My Suburban has had a bad rear main seal since 2007 or so. I don't drive it enough to bother fixing it... it might take me 2 or 3 years to get to 2500 miles.
 
slacktide said:
Well I guess you found out why you are going thru a quart of oil every 2500 miles. My Suburban has had a bad rear main seal since 2007 or so. I don't drive it enough to bother fixing it... it might take me 2 or 3 years to get to 2500 miles.
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There isn't enough to say it is the 1 qt in 2500. if it were, it would be all over the under side. it's not. I did check to see the oil level was OK and Find that the engine is over filled.

No more Jiffy lube oil changes for me.
 
Tom-D said:
There isn't enough to say it is the 1 qt in 2500. if it were, it would be all over the under side. it's not. I did check to see the oil level was OK and Find that the engine is over filled.

No more Jiffy lube oil changes for me.
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Overfilling can cause a leak. If it's seriously overfilled, I'd give it an oil change and clean up the back of the engine, and see if it recurs. If it's only slightly overfilled, it won't help.

I'm presuming the oil looks like oil. If it's fuel or coolant fouled, you found a serious fault.

It's very difficult to tell a rear main leak from a torque converter, transmission, or hydraulic clutch leak. They are different fluids, but they get so dirty you really can't tell unless you get right in there -- and oil dye can help. It's often difficult to distinguish the very common oil pan leak as well. 4WDs usually can't be repaired without pulling the engine, but sometimes 2WDs can.
 
MAKG1 said:
Overfilling can cause a leak. If it's seriously overfilled, I'd give it an oil change and clean up the back of the engine, and see if it recurs. If it's only slightly overfilled, it won't help.

I'm presuming the oil looks like oil. If it's fuel or coolant fouled, you found a serious fault.

It's very difficult to tell a rear main leak from a torque converter, transmission, or hydraulic clutch leak. They are different fluids, but they get so dirty you really can't tell unless you get right in there -- and oil dye can help. It's often difficult to distinguish the very common oil pan leak as well. 4WDs usually can't be repaired without pulling the engine, but sometimes 2WDs can.
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Its engine oil.
and the rear seal on the 3.8 V6
is changed by removing the tranny/transfer case.
 
Tom-D said:
Today while crawling around under the jeep I discover I have a rear main seal leaking. That will require a transmission and transfer case removal. I'm simply not up to that. bummer.. seeing as the "Y" pipe must come down to do the rear seal ?? it will all get completed at one time.
This will be the second time the tranny has been out. :(
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Every Jeep I ever owned had a rear main seal leak. Never fixed them either. I just let them mark their territory like a Harley.

Waste of time and money to try to patch up a bad design unless it leaked enough to cause a problem between oil changes.
 
denverpilot said:
Every Jeep I ever owned had a rear main seal leak. Never fixed them either. I just let them mark their territory like a Harley.

Waste of time and money to try to patch up a bad design unless it leaked enough to cause a problem between oil changes.
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it has never leaked before this oil change
 
GlennAB1 said:
Y would you tell us about your Tranny coming out...
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Because it will all happen at the same time. and it was found to be needed while trying to determine what needed to be done to change the Y pipe?
 
I don't see how a Y pipe could do anything to cause a cat efficiency code. As I said if you don't have any other problems it's either a bad cat or (more likely) a bad O2 sensor. An O2 sensor simulator might fix it (worked in my daughter's Toyota, didn't work in my other daughter's Saabaru)... it depends on how sophisticated the computer is in what it expects to see from the sensor.

Rear main seal went on my CJ5, covered the trailer I was towing with oil. It was relatively easy to replace without pulling the engine or tranny. But that was the straight 6.
 
It snowed in hell and I actually have a new car now. But I've had my share of old cars, so I feel your pain.

There's a product called CATACLEAN that is the only gasoline I know of that actually does anything other than stabilize the fuel or douche out the fuel system. If used as directed, it more often than not will clean out a CAT enough to get rid of the MIL. The problem is that it sometimes burns holes through your exhaust system in the process. I suppose it could also burn up the CAT itself, but I've never actually heard of that happening.

The local rednecks swear by it in their beaters. I used it once in an old Sportage and it did, in fact, extinguish the MIL. I'm pretty sure it also burned a hole in the muffler. At least the timing would suggest that. No worries. That's what muffler tape is for. I'm pretty sure that "temporary" repair was still on the car when I sold it.

I think it's just some mixture of acetone and toluene, judging by the smell. Putting some lacquer thinner in the gas to clean out the CAT is another old trick, so I wouldn't be surprised if that's all that CATACLEAN is.

As for the rear seal, some of the "high-mileage" synthetic oils actually work. Jeeps are notorious for oil leaks. At your loss rate, I probably would try a good high-mileage oil before I'd replace the seal.


Rich
 
Dana said:
I don't see how a Y pipe could do anything to cause a cat efficiency code.
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The Y pipe has the 4 cats welded into one assembly. I'm not going to try to replace each cat, and get it welded to fit properly.
that's a PITA
 
Tom-D said:
The Y pipe has the 4 cats welded into one assembly. I'm not going to try to replace each cat, and get it welded to fit properly.
that's a PITA
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Sorry if I missed it Tom, is this a manual or auto trans?

If manual, it's not unheard of to get an engine code in traffic as a result of the engine lugging briefly at low rpm/working the clutch/etc. I remember one of the auto magazines talking about it on a car (5.0 mustang if memory serves).
 
Omalley1537 said:
Sorry if I missed it Tom, is this a manual or auto trans?

If manual, it's not unheard of to get an engine code in traffic as a result of the engine lugging briefly at low rpm/working the clutch/etc. I remember one of the auto magazines talking about it on a car (5.0 mustang if memory serves).
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I have a code reader, used it to get the codes, that code says the cat is not as efficient as it should be. So.. I reset the light, and will wait until it comes on again.
 
Tom-D said:
it has never leaked before this oil change
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Well, neither did the one I bought brand new until one day it did. Heh. Welcome to Jeep ownership!

Obviously if you think it's too new and/or leaking too much, I'm not telling you not to fix it, I'm just saying that I've never had a Jeep that didn't do it.

Not pre-Chrysler and not afterward... and I'd probably still be driving the last Cherokee with its leak if I hadn't given it to my sister.

They all started around 70,000 miles. Couldn't tell ya the history of the first two, but I know the last one was taken care of any not abused since I owned it from day one off of the lot.
 
denverpilot said:
Well, neither did the one I bought brand new until one day it did. Heh. Welcome to Jeep ownership!

Obviously if you think it's too new and/or leaking too much, I'm not telling you not to fix it, I'm just saying that I've never had a Jeep that didn't do it.

Not pre-Chrysler and not afterward... and I'd probably still be driving the last Cherokee with its leak if I hadn't given it to my sister.

They all started around 70,000 miles. Couldn't tell ya the history of the first two, but I know the last one was taken care of any not abused since I owned it from day one off of the lot.
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In the morning I intend to flush the bell housing interior, clean up the mess, drain the oil and replace the proper amount. then see how long it takes to come back.
 
You are really going to bum if you change those cats and the light comes on again.
 
PaulS said:
You are really going to bum if you change those cats and the light comes on again.
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You bet,, that's why I will wait until the check engine light can't be re-set and stay out.

for now I'll clean up the oil leak and see how long it takes to reoccur.
 
Tom-D said:
You bet,, that's why I will wait until the check engine light can't be re-set and stay out.

for now I'll clean up the oil leak and see how long it takes to reoccur.
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You may already be there.

Get your favorite scanner out and see how much time you have between "all tests completed" and the MIL.

The reason you're seeing a delay can easily be because you haven't satisfied conditions for the cat efficiency test yet. It takes a while. You can try to perform a "drive cycle" to speed it up.

Cats very seldom just die. They get killed. Something else is causing your code, and you really should find it first, or it will kill your replacement, too.
 
MAKG1 said:
You may already be there.

Get your favorite scanner out and see how much time you have between "all tests completed" and the MIL.

The reason you're seeing a delay can easily be because you haven't satisfied conditions for the cat efficiency test yet. It takes a while. You can try to perform a "drive cycle" to speed it up.

Cats very seldom just die. They get killed. Something else is causing your code, and you really should find it first, or it will kill your replacement, too.
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Drove it 60 miles this morning, no light.
 
Tom-D said:
Drove it 60 miles this morning, no light.
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Not enough.

Here is an example of a Jeep (Cherokee) drive cycle:

http://www.smogtips.com/smog-question/2839/Jeep-Cherokee-Emission-Monitors-Not-Ready

Here's the relevant monitor:
Catalyst Monitor Drive Trace

Pre-Conditioning Requirements:

- MIL must be off.

- No DTCs present.

- Fuel level is between 15% and 85% full.

- ECT above 70º F.

- Engine must have run at least 90 seconds

- Engine between 1,350 & 1,900 rpm.

Driving Procedure

1) Idle vehicle for five minutes (to reach normal engine operating temperature and closed loop operation).

2) Drive with a steady vehicle speed between 30 & 45 mph for 2 minutes.
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Did you do all that in your 60 mile drive, or did you fill the tank and drive for an hour at highway speed, and then park?

Even if you did, you need to connect a scan tool to see if the monitor actually ran, before assuming your MIL is fine. If it wasn't run for any reason (including an unrelated fault -- not all potential faults set DTCs, and even those that do sit in a "pending" state for at least a drive cycle), your test is inconclusive.
 
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It's a test that monitors the switching of the 2nd o2 sensor. Could be a leaking injector or an air leak. I'm telling you, for me the issue was the PCV valve not closing properly allowing extra air in beyond the MAP sensor in my Grand Cherokee. It caused a P013C code, o2 sensor 2/2 slow to respond. But it also caused the P0430 code, though not as often. Were I faced with a cat issue again, it's the first thing I'd replace. These issues start out slow, you get a few thousand between mil trips, then it goes down to a hundred miles. I would also check the EGR valve and tube. The valves can stick after a while, there's a parameter you can watch on the scanner to see the lag if you have one, at least there was for the Hemi. Doesn't set a code.
 
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