I have a persistent P0443 code on my 2000 XJ8, and I'm at my wit's end trying to figure it out. Granted, I'm not the foremost expert on emissions, but... Sorry in advance for the lengthy post, but I want to be thorough...
Little history... Got the car last summer after it had been parked for 5+ years with the timing tensioner issue. Fixed that and a litany of other maintenance issues "while I was in there," and upon the first fill-up in early October the P0443 code popped. No biggie, I thought, I have until June to fix it before having to go for EPA inspection. Well, here we are...
As part of the initial repair work, the car got all new coils, plugs, air filter, fuel pump, relay, and filter, thorough cleaning of the entire throttle body assembly, and new vacuum lines around the throttle body including the one to the purge valve. After the code fired, I replaced the purge valve with a brand new OEM unit and also replaced the small sections of rubber hose going into and out of the valve. New jubilee clamps on both hoses as well. Still throwing the code. Next I replaced the valve that's attached to the output side of one of the vapor canisters, again with OEM Jaguar part. Still code..... Drove the car all winter this way. The only operational issue seemed to be that the car runs pretty rough when cold -- basically chugs and wants to die, but smooths out once warmed up. Last month, I scored some needed parts from a car that was being parted out a few hours away. Car had been driven to the yard, and seemed pretty clean (wish I had space! I would've taken the whole car home). I grabbed both vapor canisters, and last weekend put them on my car. The original ones smelled pretty heavily of gas, and the "new" ones didn't smell much at all so I was hopeful. Unfortunately, as soon as the car ran through the diagnostic cycle old P0443 came back.
At this point I have no more ideas. My wife (it's her car) suggested we could take it to a shop, but I don't even know if any shop in my area is qualified to work on one of these cars (I'm near St. Charles, IL). I need to get this resolved -- the registration expires end of June, and it needs to pass inspection from the Illinois EPA before I can renew...
Help??

Thanks

Steve

 

Hi Steve, here's a link from a P0443 search top right of each page. I do 2 generally, because the 2nd one came back with a little more, though the 1st one seems generally direct to your issue. Being that you replaced one part of the EVAP system, you've seemingly found the next weakest link.

https://www.jaguarforums.com/forum/tags/p0443/

https://www.jaguarforums.com/forum/s...rchid=12207606

 

I picked up a new OEM Jag gas cap today. The rubber seal on the old one was a bit questionable, so I figured while it's unlikely to be the problem (gas cap code is normally P0457) it can't hurt to replace it. Or, as my wife pointed out, better to try it than take it somewhere and have a mechanic charge me his labor to replace it...
I reset the code again. We'll see if that changes anything. If not, I'll be checking anything under the hood that looks like a vacuum line.
Any other suggestions are welcome.....

Thanks
-Steve-

 

The purge valve or a number of other little things could be the issue. I get the 455, I have to replace the balance tube between the canisters, I just don't want to get under the car right now.
You may want to check the breather lines around the filler neck also since you just did the pump. You never know, maybe one didn't get fully applied?

If you don't have it, here's a link to bookmark... JagRepair.com - Jaguar Repair Information Resource

These may help, but smoking it will be your best approach.

 

Highhorse,
I've already replaced the purge solenoid, both short pieces of hose to/from it, the vacuum line from the throttle body to it, both canisters, and the close valve. The computer hasn't run its full cycle yet since replacing the gas cap, so the light is currently off. I will check the lines around the filler neck as well as any vacuum lines underhood (on the chance a cracked, seemingly unrelated line would affect all vacuum lines) when/if it comes back on. At that point I'm pretty much out of ideas...
Like you suggested, it may be time to visit a shop. Much as I hate that idea...

-Steve-

 

Sorry, yes you did state that...I forgot to go back and find these old post diagrams at the filler neck and tank. But, here ya go....hopefully this helps.

I believe this first one is an earlier version, its been awhile since I researched this.

 

Predictably, the new gas cap did not fix the problem. So I guess it's time to start looking at all the various vacuum lines etc.
Sitting here thinking about it, is it possible for the pressure relief pipe (#2 in the diagram above) to be plugged with gas, water, whatever? Looking at the diagram, it seems that liquid could accumulate in the downward loop of that pipe and if it did how would it get out of there? And if it was plugged with liquid, how might that affect the evap system in general?
I'm just considering possibilities at this point..... This car sat outside without moving for over 5 years before I got it. The drain in the fuel filler recess was completely plugged when I got it, and had been for who knows how long. I'm just wondering if rainwater could get down the relief pipe over time and then what would happen.....
Rainy day today, so I might not be able to do much more than speculate on it today. I'm also considering investing 150 bucks in a smoke machine -- looking at a Stinger brand. For the cost of an hour's labor at a shop I can own the thing they would use to tell me "you have a leak in the evap system and we can fix it for X00 dollars".....

 

I cannot give you an answer on that...it would seem something could get into it?

Here's another screen shot to review....

 

I'm still struggling with this P0443 code. It seems whatever I try has no effect..... So far, here's what I've done:
Replaced canisters with same-age used ones, but in better shape than mine. Replaced canister close valve. Replaced purge valve and vacuum line to throttle body. Replaced the 2 pieces of hose that connect the purge valve to the vapor lines. Replaced any fuse that seemed related to emissions. Replaced gas cap. Checked the intake and both the primary and secondary vent lines for cracks, all good. Also all open and clear. Replaced o-rings on everything I could find. Cleaned MAF, and repaired its wiring harness which had frayed wires. Checked the vac line to the purge valve, and it has plenty of vacuum. Blew through all the purge lines to confirm they're clear. My son checked the wiring to the purge valve, and confirmed it's getting power and it also seems to have proper resistance.
Right now I am stumped. I have until the end of the month to resolve this and get the car through emissions testing.
I have a new neighbor friend who has graciously offered use of his smoke machine. Does this seem like a logical next step or is my problem likely beyond a vacuum issue? If I do try it, where would be a good spot to connect it?
Thanks for all the advice so far. By the time I figure this out, I think I'll (unintentionally) be something of an expert on the X308 evap system.....
-Steve-

 

If I had the smoke machine, I'd of done that first...one Q, when you clear the code, does it come back immediately or does it take time?

 

The code came back after probably 40 miles -- one round-trip to work, and part of the next day's drive in. Mix of 45-50 mph surface streets and some 75-80 mph interstate

 

This should be a hard code then...that meaning it is either such a failed part or leak, that it should be noticeable. My P0455 is extremely intermittent, like almost a year sometimes, so mines a soft code and a small leak.

Could you clear the code just before pulling in the driveway of the station and get past inspection with that...then claim ignorance if it goes off?

It seems probable it only happens at higher rpm speeds as you state. In that case clearing it just before entering the shop, then the lower rpm idle into the booth should get you past inspection and buy you time for the next one?

 

If I could clear it and get through the test, I would absolutely do it. However, Illinois plugs into the OBD port rather than use a sniffer or other method. If the computer hasn't finished its test cycle, you get a "NO TEST" from the EPA which is, essentially, a fail. One pending I/M monitor is OK, 2 is not. Based on what I've seen with this car, the last 2 tests to run are the cats and the evap. They both run in such rapid succession it's pretty unlikely I could get it to run the cat and then get through the line and tested before it runs evap

 

Time for another update......
I got my hands on a smoke machine and blew smoke in a few places this morning. First I tried the intake. I pulled the MAF off and adapted to fit the smoker's nozzle into the intake hose right there. After a couple minutes, I was getting a little smoke out of the primary breather tube right at the connector where it goes into the passenger-side cam cover. I pulled it off and replaced the O-ring (again.... Now the 3rd different O-ring on that hose...), this time with one slightly bigger in section. Popped it back on and the leak continued. I could wiggle the connector around and the smoke would stop or diminish. It was also leaking a little where the corrugated hose joins the 90-degree connector. Rather than continue to fiddle with trying to seal it up, I ordered a new one which should be in Tuesday. Meanwhile I may try wrapping it up with electrical tape.
I also had a more significant leak where the intake joins the throttle body. Despite the fact the 2 bolts are (very) tight, I was getting a good amount of smoke there. As with the breather, I could push down on the intake and diminish the amount of smoke. I've known all along that this joint isn't really tight, but didn't think much of it. I ordered a new intake boot seal.....
QUESTION ----- Is it possible that these 2 leaks could cause the P0443 code?
I also plugged the smoker into the evap line that comes up from the canisters to the purge valve. The only smoke I got was an occasional puff near the passenger rear wheel, which I take to be the vent and assume to be OK. I also plugged it onto the vac line that feeds the purge valve (at the purge valve end, pushing smoke back towards the throttle body) and got nothing.
So what do you think?
Thanks

-Steve-

 

Glad you got on that smoke machine...I went by my Tech yesterday to ask him about this. I explained all you had replaced and he stated an obvious point that the newer stuff doesn't mean it is good. My Q to him was about the purge valve and voltage readings vs it still possibly being bad (since the code is a 443). He said sure, but then he got into what you've described. His statement.... "...about the only sure way is to smoke it...there could be bad ring seal(s) (as you found), cracked lines, ..even the purge could leak but meter properly."

 

Well here's to hoping the leaks I found today are the culprit(s). Parts come in early in the week, so I'll get them in right away and reset the code. By the end of the week the car should have run all the diagnostics so I'll know if it's OK or not.

Thanks!

-Steve-

 

It appears I've stumbled upon the fix for this problem. While rigging up a way to connect the smoker to the intake snorkel, I noticed what I thought was a considerable amount of oil in the snorkel on the throttle side of the MAF (like a teaspoon's worth). I cleaned it up, and posted a question here asking if there should be that much oil there. The answer was, some but not very much. Then I was directed to the TSB referring to cleaning the part-load breather, which I did and found it to be clogged. It had probably never been cleaned. I re-set the code, mostly to clear the brake-switch failure code since I replaced it, and figured the P0443 would come back. At that point I really thought it was going to be either the leak in the full-load breather or the boot seal on the intake that would be the cause of the code. Sunday, we took a short road trip of about 250 miles and the light stayed off. When we got home, I plugged the OBD reader in and it showed all tests had been run and NO CODE! We were waiting at the door when the EPA facility opened Monday morning, and it has passed its emissions test so I can renew registration and carry on.
Special thanks to Highhorse for the ongoing advice,, and to Nilanium for pointing out that TSB. You guys are great!

-Steve-

 

I am so stuck with this code, Just looking for some ideas or others who have had the same problem that can help me. po443 code on a 2001 jaguar xj8