I've recently ended up with a 2004 X type 3.0 AWD after a storage lien and body shop repair lien on a customer's vehicle. Low and behold, I now own it. However, I need to get rid of a few gremlins...9 months ago the car hit a rock on Malibu Canyon, cracked the radiator and kept going. The owner (older lady) drove it like that for about 2 to 3 weeks. Eventually, it overheated. According to the receipts in the car, a new radiator, thermostat and a new head + head gasket was installed. After which it was brought to us in order to re-paint the fender, change the front bumper, replace broken fog lamp etc. etc. After 9 months of trying to recover our balance, we finally ended up with the car. Now for the gremlins: After sitting for 9 months, the car started right up (with a jump) and drove like a champ, the only issue detected was a bit of rough idle. One day later the check engine came on with a misfire in cylinder 4 and 6. I checked the plugs, and they are new. The car drives excellent, plenty of power, shifts fine. It has a ROUGH idle when stopped in gear, it does not stall but you can feel it. I have checked all the common culprits: air leaks, PCV, coils (replaced them) and nothing, I even emptied out the fuel tank. I can re set and the codes come back 1 to 2 days later. Lately I got a P0402 (Catalytic below trshold bank1). I am running out of ideas? Any help would be appreciated!
2004 X Type with 55K miles on it

 

cartopics, I would first try replacing the fuel filter for the car. With it sitting as long as it did, very possible that stuff settled and is now clogging up the fuel filter. After that, I would say to pull the upstream O2 sensor for the cat located between the engine and the firewall (this is bank 1) and give it a look/cleaning. It is possible you had a critter crawl up there and crew on a wire or two. May even be a good idea to pull the downstream O2 sensor and give that a look/cleaning. Almost all the reasons for this failure involve the O2 sensor. The other one is cat has died on you. I guess it is possible that if she drive the car for awhile with no coolant in it, she could have hurt the cat. But, I would venture to guess that with all the engine work, someone forgot to plug the O2 sensor back in. But, that is just a logical guess on my part.

Hopefully this gets you going in the right direction.

 

I will give it a go tomorrow again...

 

OK. Brand new day and brand new O2 sensors...No luck. I am running out of options - I can only think of a bad fuel injector and maybe a completely shot catalytic convertor? I can probably disconnect the catalytic and run the engine, check if the rough idle evens out...

 

I forgot to mention: I hooked up a vacuum/smoke tester - No vacuum leaks in the system

 

cartopics, to save yourself a little bit of trouble, for the fuel injector leak problem, I would install a fuel pressure gauge on the test port and then just turn the car to the RUN position. From there, the pressure should jump up to about 40 psi. Then after a few seconds, you can turn the car off and you should see the pressure fall off slowly (from 40 to 0 psi over about 30 seconds or so). If you see it fall off rather quickly, then you know you have an injector issue. But, based on the code that you are getting, I am leaning more towards a bad cat. If you only had an injector sticking, the car would see that as an injector issue and give you a different code than P0420.

 

Thanks...I'll try that tomorrow. What about my idea in regards to the Cat? If I disconnect and and run the engine...The misfire should go away if the Cat is at fault...Correct?

 

cartopics, you may find that running the engine without the cats installed will cause other issues. The O2 sensors for this car are actually inside the cat for the upstream O2 sensor. So, without the O2 sensor in the exhaust path, you may find that the car is going to run really rich as it will think that the car is running super lean due to the O2 sensors being out in the open air. You can try it, but don't be surprised if other problems arise. I would think you might be able to get away with breaking the joints between the cats and the exhaust headers and installing say a 1/4" longer bolt so that you have most of the exhaust going out the gap and some being pushed through the exhaust system. That should remove most of the back pressure a bad cat would create and allow the engine to run normal (granted, fairly loud).

 

I will give it a try...After i come back from fishing. Monday sounds like a good day.

 

Thermo, I just tried a different scanner (Innova) and I picked up a new code which my SnapOn didn't see it: a P1316 along with the Cylinder 2, 4 and 6 misfire. Any ideas?

 

cartopics, the P1316 code is a low efficiency of the cat (bank 2) code. So, with that being said, it is very likely like you have a bad cat in the car. Plan to drop about $1000 for a new cat. Unfortunately, the cats in these cars is pretty unique, so a generic cat is not going to do it for you unless you do a lot of customization and switch over to a Ford 3.0L exhaust setup and move the cats to under the car. Probably more effort than it is worth.

 

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