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View Full Version : P0443 code, any help?



muddeprived
07-23-2009, 08:16 AM
P0443 : http://www.obd-codes.com/p0443

It just popped up today. I've been having a rough idle when I start it up every morning. It only lasts for about 4 seconds and then it idles normally. I'm not sure if that's related but I doubt it.

The code popped up, i scanned it, then erased it and it's back again everytime i restart the jeep. My haynes manual says nothing in it about this issue or where to check. Any ideas?

ol"blue
07-23-2009, 12:35 PM
As far as our talk, I'm sure the charcoal canister is in the engine compartment-usually near the rad core support at the frame level. A round black plastic "can" about 5" in dia. with 3 or 4 vac lines going to the top. The only reason it would become contaminated with liquid fuel would be the rollover/safety vent valve in top of the fuel tank going bad/missing, allowing liquid instead of vapors into the canister when gas tank is over-filled. That would cause an over-rich condition upon start-up, which would go away soon after starting. JMO

muddeprived
07-23-2009, 12:44 PM
As far as our talk, I'm sure the charcoal canister is in the engine compartment-usually near the rad core support at the frame level. A round black plastic "can" about 5" in dia. with 3 or 4 vac lines going to the top. The only reason it would become contaminated with liquid fuel would be the rollover/safety vent valve in top of the fuel tank going bad/missing, allowing liquid instead of vapors into the canister when gas tank is over-filled. That would cause an over-rich condition upon start-up, which would go away soon after starting. JMO

this "over-rich" condition, would it cause a rough idle at startup? That's what I have but only for a few seconds after I start it then it's fine.

ol"blue
07-23-2009, 12:51 PM
this "over-rich" condition, would it cause a rough idle at startup? That's what I have but only for a few seconds after I start it then it's fine.

Yep. Just for a few seconds/minutes. Then it would clear up. It's kind of like back in the carb days when you had a sticky choke. After the initial start-up it clears the over-rich condition and runs fine. Find the canister purge line that goes to the manifold/throttle body whichever you have and disconnect and plug the resulting vacuum leak. Then start it up and see if the condition goes away.

Mudderoy
07-23-2009, 12:55 PM
You still have that little black bomb looking thing that was/is in the bumper connected?

muddeprived
07-23-2009, 12:56 PM
Yep. Just for a few seconds/minutes. Then it would clear up. It's kind of like back in the carb days when you had a sticky choke. After the initial start-up it clears the over-rich condition and runs fine. Find the canister purge line that goes to the manifold/throttle body whichever you have and disconnect and plug the resulting vacuum leak. Then start it up and see if the condition goes away.

I'm gonna have to try that tomorrow morning cuz it only does this (rough idle) first thing in the morning. It won't do it the rest of the day unless it sits for a long period of time, like overnight.

muddeprived
07-23-2009, 12:56 PM
You still have that little black bomb looking thing that was/is in the bumper connected?

yeah...is that related?

Mudderoy
07-23-2009, 01:12 PM
Well I didn't mention it before, because I didn't think so, but someone mentioned a vacuum leak and removing that would be a big vacuum leak.

ol"blue
07-23-2009, 01:14 PM
This scan is for a ZJ, but it's just to give you an idea of the layout of the system. Yours might not have the purge solenoid, but the basic idea and possible location of the canister is there. I can't find a suitable pic/scan of the set-up on an XJ.
If this shouldn't be on here please delete it.
http://i562.photobucket.com/albums/ss68/DLHTURBO/img070.jpg

ol"blue
07-23-2009, 01:23 PM
Well I didn't mention it before, because I didn't think so, but someone mentioned a vacuum leak and removing that would be a big vacuum leak.

A vacuum leak (like the axle disco vacuum reservoir being unhooked), would cause a lean condition all the time, not an over-rich condition that was only present on initial start-up. A lean condition would exhibit an increased RPM at idle, as well as spark-knock under load, and increased operating temps. IMO

muddeprived
07-23-2009, 01:36 PM
ok I went out there to take a look at stuff. Honestly I am quite confused. I really need a picture showing what hoses go to what. I have a big silver canister right next to the solenoid. is that the evap canister?

I'm just gonna go take some pictures and hopefully someone can show me what is what. I hate motor work.......

muddeprived
07-23-2009, 01:46 PM
http://i37.photobucket.com/albums/e73/muddeprived/cherokee/p0443/DSCF6365.jpg

http://i37.photobucket.com/albums/e73/muddeprived/cherokee/p0443/DSCF6368.jpg

http://i37.photobucket.com/albums/e73/muddeprived/cherokee/p0443/DSCF6369.jpg

http://i37.photobucket.com/albums/e73/muddeprived/cherokee/p0443/DSCF6367.jpg

muddeprived
07-23-2009, 01:48 PM
I've been reading the Haynes manual. It says the most common problem with emission related issues is a stuck egr valve. What da heck is this valve? The picture shown in the haynes manual doesn't really match up to anything I can see with my eyes. can't find it anywhere.

Melissa
07-23-2009, 02:05 PM
I've been reading the Haynes manual. It says the most common problem with emission related issues is a stuck egr valve. What da heck is this valve? The picture shown in the haynes manual doesn't really match up to anything I can see with my eyes. can't find it anywhere.

EGR- Exhaust Gas Recirculation

High combustion temps raise the level of oxides of nitrogen (NOx) emissions in the exhaust. The EGR system lowers NOx levels by allowing small amounts of exhaust gas into the combustion chamber to reduce combustion temps.

The EGR valve is a backpressure or vacuum controlled device which regulates the amount of exhaust gas bled into the intake.

The EGR valve is usually open during warm engine operation and anytime the engine is running above idle speed.

ol"blue
07-23-2009, 02:13 PM
In the 1st & 2nd pics the alum. thing is part of your A/C. The thing to it's left, right in the pics, with the "service port" tag is the purge canister solenoid. Your EVAP cannister is probably mounted under your air cleaner like it is on my ZJ. You'll be able to see it from underneath. It's black plastic, about the size of a quart juice can. It's bolted in from the top though.

Melissa
07-23-2009, 02:23 PM
In the 1st & 2nd pics the alum. thing is part of your A/C. The thing to it's left, right in the pics, with the "service port" tag is the purge canister solenoid. Your EVAP cannister is probably mounted under your air cleaner like it is on my ZJ. You'll be able to see it from underneath. It's black plastic, about the size of a quart juice can. It's bolted in from the top though.

The "black bomb" would not be the vacuum canister that was mounted in his bumper when he swapped bumpers, would it??

http://i730.photobucket.com/albums/ww305/melreese83/videos/DSCF5940.jpg

muddeprived
07-23-2009, 02:37 PM
In the 1st & 2nd pics the alum. thing is part of your A/C. The thing to it's left, right in the pics, with the "service port" tag is the purge canister solenoid. Your EVAP cannister is probably mounted under your air cleaner like it is on my ZJ. You'll be able to see it from underneath. It's black plastic, about the size of a quart juice can. It's bolted in from the top though.

Ok I had the air cleaner off a couple days ago and I don't remember seeing this canister but I wasn't really looking for it so I'll check again.


Here's an update:
I went out and cleared the code and restarted it. The code came back on. I was told in my local forum to check for clicking coming from the purge canister solenoid. It was not clicking (i can't hear it but i should be able to feel it). I fiddled with all the hoses and checked for anything loose. I also checked all the connectors and no corrosion was visible. They all still had the dielectric grease on them. After I got done blackening my hands, I erased the code and restarted the jeep. No CEL came on. I drove it a couple miles, hard and soft, shut it off and back on, and the code never came back. So....i'm thinking maybe a hose was slightly loose or something, throwing the code. I dunno but the dash isn't a partial-lit xmas tree anymore so I'm gonna wait and see if it decorates itself again later.

I'm gonna run a can of seafoam in the tank and also some in the TB to clean out my injectors and stuff. Maybe that'll cure my slightly rough idle.

ol"blue
07-23-2009, 03:15 PM
The "black bomb" would not be the vacuum canister that was mounted in his bumper when he swapped bumpers, would it??

http://i730.photobucket.com/albums/ww305/melreese83/videos/DSCF5940.jpg

Isn't that for the vacuum disconnect on the front axle? The EVAP canister is shaped like a can, or cylinder, that's flat on the ends.
Hopefully you've solved your problem, but the purge solenoid is supposed to rhythmically click while the engine is idling. It almost sounds like a stuck lifter but not so loud.

Mudderoy
07-23-2009, 03:37 PM
I don't have a vacuum disconnect yet I have this little black spheroid. I thought it was for storing of additional vacuum for those times that vacuum is low due to high engine demand.

ol"blue
07-23-2009, 04:06 PM
I don't have a vacuum disconnect yet I have this little black spheroid. I thought it was for storing of additional vacuum for those times that vacuum is low due to high engine demand.

If so, it would be helpful when braking with a stalled engine.

muddeprived
07-23-2009, 04:11 PM
I always thought it was a bomb that would explode if you didn't modify your jeep....so i modified mine in a hurry.


Or was that the jeep bug doing it's thing.......I dunno.

whocares8310
01-27-2011, 07:15 AM
the little black bomb is the vacuum canister for your ac and cruise control if you have it

just in case anyone read this and was worried about what would happen if they misplaced it along with their bumper.