Clogged Cat?
#1
Clogged Cat?
I'm trying to do some homework for my father.
He has a '98 2500 with a 360. We were using is a week ago and it out of the blue started idling like crap, it also had to be cranked more then usual to get it running.
I went to filled it up and on the drive back the CEL came on, it started to run like crap while under way and at one point the CEL flashed at me. This was all in the 5 or so miles back from the filling station.
Put the the thing away and talked it over with him and deiced to run it over to out usual mechanic. He got in the next day and it was dead, just spins over and pop every now and then but wasn't even close to catching. Had it towed over to the shop.
The mechanic did all the usual stuff, plugs cap rotor...nothing. Then he went for a cam sensor and crank position sensor, as you can see the part list is starting to add up.
After checking with some folks who work on dodges and of course googling I came up with two things, ignition coil and clogged cat. He tried a new coil and that didn't help... He then pulled the 02 sensor and it started so he replaced that and sent us on our way (we were all rushing to get ahead of this big snow storm). It's kind of back to where we where a few days ago, it will run but it idles like crap. We're not sure how it pulls since it's was snowing like a bugger and didn't want to end up in the ditch. It's also smells kinda funny idling, slight rotten egg thing going on.
The more I look at things the more I think it's the cat, I mean it seems like all the pieces fit right?
The other weird thing is by the time the mechanic looked at it the CEL was off and he couldn't pull any codes.
Boy is this thing driving us nuts!
K
He has a '98 2500 with a 360. We were using is a week ago and it out of the blue started idling like crap, it also had to be cranked more then usual to get it running.
I went to filled it up and on the drive back the CEL came on, it started to run like crap while under way and at one point the CEL flashed at me. This was all in the 5 or so miles back from the filling station.
Put the the thing away and talked it over with him and deiced to run it over to out usual mechanic. He got in the next day and it was dead, just spins over and pop every now and then but wasn't even close to catching. Had it towed over to the shop.
The mechanic did all the usual stuff, plugs cap rotor...nothing. Then he went for a cam sensor and crank position sensor, as you can see the part list is starting to add up.
After checking with some folks who work on dodges and of course googling I came up with two things, ignition coil and clogged cat. He tried a new coil and that didn't help... He then pulled the 02 sensor and it started so he replaced that and sent us on our way (we were all rushing to get ahead of this big snow storm). It's kind of back to where we where a few days ago, it will run but it idles like crap. We're not sure how it pulls since it's was snowing like a bugger and didn't want to end up in the ditch. It's also smells kinda funny idling, slight rotten egg thing going on.
The more I look at things the more I think it's the cat, I mean it seems like all the pieces fit right?
The other weird thing is by the time the mechanic looked at it the CEL was off and he couldn't pull any codes.
Boy is this thing driving us nuts!
K
Last edited by kopeck; 02-08-2013 at 10:16 PM.
#2
#3
^ note that running without the front O2 sensor will set a code and turn on the CEL, but ignore it and see if it runs. if it does, you can drive it and it'll run ok, but it'll be worse than usual on mpg.
the missing front O2 gives the exhaust pressure a way out to overcome a stopped up cat.
the missing front O2 gives the exhaust pressure a way out to overcome a stopped up cat.
#4
^ note that running without the front O2 sensor will set a code and turn on the CEL, but ignore it and see if it runs. if it does, you can drive it and it'll run ok, but it'll be worse than usual on mpg.
the missing front O2 gives the exhaust pressure a way out to overcome a stopped up cat.
the missing front O2 gives the exhaust pressure a way out to overcome a stopped up cat.
Do you think plowing will be a problem with out the O2 sensor? You don't work the engine all that hard...the transmission on the other hand...
I've had to run my car with sensors unplugged before, I know it's not ideal but the controls are smart enough to use a safe baseline to get by.
K
#5
If the CEL flashes, stops flashing, and flashes again, with no consistent pattern or consistent number of flashes, then I suggest having the exhaust pressure tested. My experience has shown the flashing CEL to be the result of a clogged cat.
#6
Do like the others have said it, pull sensor to relieve pressure.
I don't know if it would be a problem to run with the Pre Cat O2 out?
It may create other issues since it is part of the emissions system.(maybe run rich) I don't know.
on a side note:
For starting issue it could also be IAC motor stuck or not working, possibly a broken linkage to the butterfly from the throttle too.
I had accidently unplugged mine a couple of weeks ago and had the same no start and pop like you described. BUT when I kept my foot on the gas it started and ran, it just Idled like crap and popped. (which is why I suggested looking at the linkage to the throttle too)
Anyway its just another thing to look at.
For codes you can try the key trick.
Turn the ignition on, but don't start the motor, then off, three times. Third time, leave it on, it will display codes on your odometer.
Write down any codes you have, last code will be PDONE.
Then check them here>>>> https://dodgeforum.com/forum/2nd-gen...code-list.html
I don't know if it would be a problem to run with the Pre Cat O2 out?
It may create other issues since it is part of the emissions system.(maybe run rich) I don't know.
on a side note:
For starting issue it could also be IAC motor stuck or not working, possibly a broken linkage to the butterfly from the throttle too.
I had accidently unplugged mine a couple of weeks ago and had the same no start and pop like you described. BUT when I kept my foot on the gas it started and ran, it just Idled like crap and popped. (which is why I suggested looking at the linkage to the throttle too)
Anyway its just another thing to look at.
For codes you can try the key trick.
Turn the ignition on, but don't start the motor, then off, three times. Third time, leave it on, it will display codes on your odometer.
Write down any codes you have, last code will be PDONE.
Then check them here>>>> https://dodgeforum.com/forum/2nd-gen...code-list.html
#7
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#8
I'm talking 30 minutes of work or so.
K
#9