2008 XC90 3.2L V6 misfires, fuel level sensor, Cat bank 1 Topic is solved

[jimmy57]

Clear and drive some more. Again 420 is the symptom and 175 is the real info but you are running rich, just to the point of code trigger on cylinders 4,5, 6.
Time to look at fuel pressure. That engine uses an "innie" schrader valve deal instead of the normal "outie" like a tire valve. In that case you can check under car using a quick connector fitting adapter at fuel filter.

[headneophyte]

I apologize but I cannot find the fuel pressure port. Under the hood I see the rail with the fuel pressure sensor on the right side and on the Left end there's only a torx head screw threaded into the rail. I followed the hard fuel line down under the car until it transferred into what looks like nylon lines that run back to the fuel tank. I cannot find a visible filter, is it inside the tank? Do I need to take out the torx head screw on the left end of the rail and thread something in? I went and rented a fuel pressure gauge but nothing on it looks small enough to thread into that torx head hole. I can provide pictures if needed. Thanks so much!

[jimmy57]

The black plastic torx is the cap over the inverted schrader valve port.
There are XC90s w/o fuel filter but you could have a plastic line junction in front of right rear tire.

[headneophyte]

I'm still here! Just working this issue. The fuel pressure gauge I rented had 10 adapters in it, but none for the XC90. There is a used import dealer in next town over who is closed on the weekends with a service department, I'm going to get it checked there tomorrow providing they have a gauge that works.

I'm tempted to close this thread as you all have helped solve the initial problem. I thank you all profusely, as replacing the MAF sensor resolved the misfire issue.

I had a 3/8th of a tank and I put in a can of seafoam. It drove nearly 40 miles code free and then the check engine light came on, but only P0420 and P0430 were present. I'm not convinced it doesn't have a fuel pressure issue as I think I can feel it stutter once in a while at higher speeds while accelerating (which my Ford truck did and it was indeed a fuel pressure issue). That may be an issue for a new thread, I don't want to have multiple issues on a single thread.

If everyone is cool, I can mark this solved and thank you all!

[pgill]

Marking the topic solved is fine, it will still be open for adding comments

I am glad to hear that the misfire is gone.

Nice work.

If you get more misfires or if you get more ignition coil failures please post here.

Also if you replace the Thermostat please post that here as well.

Another 3.2 owner had coil failures and he fixed the problem by replacing the Thermostat.

I am very curious to see if replacing the MAF can solve the coil failures also.

I do recommend that you inspect your Spark-plugs after driving ~1000 miles to make sure that everything is working well

Good Luck

Paul