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Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go hereXJ (84-01)
All OEM related XJ specific tech. Examples, no start, general maintenance or anything that's stock.
So i recently got this 2001 XJ Sport. I really like it, but of course being 22yrs old it has its gremlins. It has a somewhat rusted rocker panel on the passenger side I'll fix a little down the road and some minor rust in the door jams but otherwise the body is pretty good especially for a NY Jeep. I used to mess around with my old Camaro back in the late 80s but never got full into it before someone smashed into me and totaled it. So, i am basically new to working on cars, but have always been interested in it and have some basic knowledge. I watched roadkill and a bunch of the (velocity)motortrend shows a lot for while. So anyways, I have been posting questions for a little bit now randomly here but though it better to have it all in one place now that I have driven it a bit and I THINK all the current gremlins have come up.
So...here is the ugly....
The muffler has a hole and it has no tailpipe. I got a new muffler and tailpipe but haven't installed them yet due to completely eradicated nuts on the old muffler/CAT connection. They are pure rust and rounded out in 2 seconds because they just crumbled. So this will be for a later date. I'll probably cut the studs since the new muffler has new ones and do it that way.
Currently I have 3 codes:
P0172, P0175, P0455
172 and 175 are bank 1 &2 running rich -- I am thinking to change the sensors since I'm pretty sure they are the originals. If its not those, what else should I check?
455 is a large EVAP leak. --So far I have changed the EVAP line form the canister to the fuel tank. P0455 still comes up. SO I need to move onto other parts of the system. what should i check next in the system? (Also...can the hole in the muffler cause this? its VERY small but it is there.)
It also always needs to be turned over twice. First time it just cranks, second time it starts. It then runs pretty rough until it warms up to temp then it seems ok. As far as the 2 time thing, from what i understand this can be the fuel pump check valve. Before i go messing with that is there anything else I should check? It has been doing this since I got it, when it was warm/hot out. But I am in NY and it is starting to cool off now. I'm thinking the rough idle when cold could be due to the 172/175 codes so, the sensors and/or plugs maybe?
I do plan to change the plugs.
The main issue here is that it hasn't been inspected due to these codes. I got this Sept 14th, had the temp 10 day extension, which has obviously expired. But id really like to get this thing in order before the very cold weather hits so I don't have to worry about it so much until Spring.
Could your gas cap be a major evap leak? You might want to check the O2 sensors, sometimes the wires get cut/broken by moving parts. Once you are under there, you can actually check the resistance I think to determine their actual status as well.
I would leave the fuel pump diagnosis to last and take care of the others first, with a cheap code reader/clearer you could crank up, clear the code and get inspected after correcting the evap leak and the O2 issue, maybe?
Could your gas cap be a major evap leak? You might want to check the O2 sensors, sometimes the wires get cut/broken by moving parts. Once you are under there, you can actually check the resistance I think to determine their actual status as well.
I would leave the fuel pump diagnosis to last and take care of the others first, with a cheap code reader/clearer you could crank up, clear the code and get inspected after correcting the evap leak and the O2 issue, maybe?
I actually JUST bought a gas cap haha. The old one seemed fine but it was the original one so one never knows.
Yea if i clear up the O2 and EVAP it should pass. So those are def top priority. Just not sure what the EVAP issue is yet, assuming its not the gas cap.
thank you sir!
I actually JUST bought a gas cap haha. The old one seemed fine but it was the original one so one never knows.
Yea if i clear up the O2 and EVAP it should pass. So those are def top priority. Just not sure what the EVAP issue is yet, assuming its not the gas cap.
thank you sir!
I had a large EVAP leak about a year ago that kept me from passing inspection. I tired and traced everything.... I finally took it to a local shop and had the EVAP system smoke tested. The culprit was the fuel valve on top of and inside the gas tank. There was a bad seal so when the EVAP system did its pressure test air would leak from there and it would not hold enough pressure to satisfy the test.. Also I know that the first thing that is suggested is a new gas cap. Make sure you get a MOPAR cap, the aftermarket ones are prone to fail.
The codes and sensors are there for a reason- to help diagnose faults. Often on old cars it’s just assumed the sensor throwing a code is bad, but before assuming that, check what it’s telling you. You have codes saying running rich and hard starts/poor idle. To me the sensor seems fine, but you likely need a tune up and throttle body cleaning. Never a bad idea to put new cap/rotor/wires/plugs on a new to you older car anyway if they aren’t obviously new. Clean your TB well, including the IAC. Start with those basic maintenance items if you haven’t already. For the evap leak, refer to the diagram on the firewall and carefully inspect all the hoses, often the rubber will dry out and crack or the steel lines at the canister rust out.
Ha thanks @Roler , i did catch that, and i do know mine has a coil rail.
thanks @poni Yea i need to do the plugs, and i will do the throttle body as well. 100% cant hurt to clean that out!
yea i need to check the lines for the EVAP. I changed the rear steel line to a rubber one (from the fuel tank to the canister) as it was very rotted out, and replaced the fuel cap, but still have the code thus far. So i have to check the rest of that system.
I got the O2 sensors cuz they are the originals on there as far as i know, and with 198K miles, i figured i should get em. I got ones from carparts.com on sale which may have been a bad idea lol, but the reviews are good so if it helps clear the codes, fantastic, if not, i have them for when i need em. Money has been tight as my old business pretty much just tanked this August. I JUST got a job that starts next week so if need be, later on i can replace these chinese sensors with OEM/Mopar/NTK. I just need something to get this dang thing to pass inspection! Luckily the job is only a 7 minute drive away lol.
The P0455 code was the one that kept me from passing inspection. I traced all the vacuum tubes, I replaced a few of the rubber fittings that had become brittle and had stretched. My metal gas line actually looked really good, but I removed it and checked for any kind of interior buildup, I also dropped the gas tank checking for bad hoses, which all looked fine and removed and cleared out the charcoal canister checking it for cracks, blockage and potential leak's, of which there were none. I also replaced the EVAP purge valve. Nothing cured the P0455 code. I was able to outsmart the emission testing process here in Atlanta for a year or so while I continued to trouble shoot this issue, as it did not seem to affect the performance of my Jeep. However, when they switched from a pure ECM mileage count to a mileage and key cycle count system, I was sunk. At that point I took it to a local shop and for about $100 I got the EVAP system smoke tested. And as I stated in an earlier reply, they found a leak on the top of my gas tank; it was attributed to the fuel tank vent valve. If I'm not mistaken the P0455 indicates that there is a large leak, meaning the EVAP system can't sustain enough pressure, long enough in your EVAP lines to pass the EVAP test. So, it assumes that you're leaking fumes. I highly recommend getting the smoke test done by a professional. I tried doing it myself by building a smoke canister and using an air compressor and didn’t find a leak, but obviously there was one. So, unless you have a massive hole somewhere the chances of finding the leak on your own are slim.
The P0455 code was the one that kept me from passing inspection. I traced all the vacuum tubes, I replaced a few of the rubber fittings that had become brittle and had stretched. My metal gas line actually looked really good, but I removed it and checked for any kind of interior buildup, I also dropped the gas tank checking for bad hoses, which all looked fine and removed and cleared out the charcoal canister checking it for cracks, blockage and potential leak's, of which there were none. I also replaced the EVAP purge valve. Nothing cured the P0455 code. I was able to outsmart the emission testing process here in Atlanta for a year or so while I continued to trouble shoot this issue, as it did not seem to affect the performance of my Jeep. However, when they switched from a pure ECM mileage count to a mileage and key cycle count system, I was sunk. At that point I took it to a local shop and for about $100 I got the EVAP system smoke tested. And as I stated in an earlier reply, they found a leak on the top of my gas tank; it was attributed to the fuel tank vent valve. If I'm not mistaken the P0455 indicates that there is a large leak, meaning the EVAP system can't sustain enough pressure, long enough in your EVAP lines to pass the EVAP test. So, it assumes that you're leaking fumes. I highly recommend getting the smoke test done by a professional. I tried doing it myself by building a smoke canister and using an air compressor and didn’t find a leak, but obviously there was one. So, unless you have a massive hole somewhere the chances of finding the leak on your own are slim.
Thanks @JohnnyMc3 ! For the P0455, Honestly i am heavily leaning towards this. I just don't really have the time to go through every part since i will be starting work. This will at least find the issue and perhaps i can fix that myself. But finding the issue, yea this may be the way to go
thanks!
Worked fabulously, but IMO smoke testers become less effective the further the leak is from the test connection. Consequently, I alternately connected it to the front, then in the back, and voila found leak 2 seconds after the rear connection.
Thanks @Dave51 i will keep that in mind, and possibly pick it up as that is likely cheaper than having a pro do it and then i'll have this if i need it in the future!
Ok so circling back, i am focusing on the running rich (P0172 &175) issue first, then i will get to the EVAP leak.
Something to note....this Jeep has the K&N air intake on it with the cone shaped filter that was installed by the PO. I noticed when i start the Jeep the intake sounds very loud like its REALLY sucking. I never had one of these before so dont know if thats normal? It also runs a bit rough for id say about a minute or a little less..then it seems to quiet down and i hear less of the suction and it smooths out considerably.
I dont see/smell any gas on the engine near the injectors.
So being new to this kind of stuff with only basic automotive knowledge, is there a "checklist of things to check" for this issue, assuming its NOT the sensors?
My plan currently is to check the air intake filter/hose and make sure its all clean and clear. Then give the throttle body and sensors on it a good cleaning/replace the gasket.
Should i just replace the MAP, TPS, and IAC sensors or just clean em up (assuming they aren't obviously damaged/destroyed)
Assuming this doesn't fix the issue, what would be next on this list to check? I just want to have a rundown list of stuff to check so when i have a day off i can go through as many as possible without asking here every other day lol.
The smoke test option is definitely the best option. You can spend a lot of money replacing parts on the EVAP through guesswork. There are multiple lines, and components in that system and some of them are pricey to replace arbitrarily.
I have the K&N cone filter on my '04 KJ.
Yes, it is the Ross Perot of air cleaners!!
(Giant suckin' sound)
Sorry, some of you probably aren't old enough for this reference.
Completely normal.
I have the K&N cone filter on my '04 KJ.
Yes, it is the Ross Perot of air cleaners!!
(Giant suckin' sound)
Sorry, some of you probably aren't old enough for this reference.
Completely normal.
Side note completely. The coolant reservoir cap just doesn't want to stay closed. its the flip up snap to close type. the old one was missing so i got an aftermarket (Dorman) one but it just wont stay closed. I snap it closed and it pops back open. Is this an issue for the coolant/cooling performance wise? I wanna say its not, but just want to make sure. I may have to find an actual OE one.
10-20-2023, 12:26 PM
My new-to-me 2001 XJ Sport. The ugly.
