2004 Volvo XC90 T6 (SUV 2.9L twin turbo).

First symptom, ECU reports #2 bank rich off idle. About 4 weeks.
Second symptom, engine stalls & rough idle - ECU reports #2 and #1 bank rich off idle.

Inspection found vacuum line disconnected from intake shortly after mass air flow (MAF) location (I still cant figure out what the hose goes to). New hose cut & line reconnected.

New symptom - ECU reports MAF failure, higher voltage than expected.

New MAF located and installed, no change in symptoms so old MAF reinstalled. Further inspection found upper intercooler hose deteriorating, hose replaced.

New symptom during test drive - about 2 miles to gas station. Drove to gas station & added 5 gallons (it was almost at redline) ... turbos were working & things seemed good except low idle rpm (600). After filling, started vehicle o.k., but shortly after engaging transmission, engine died & ran rough.

Limped home & ECU reported previous errors plus misfire in cylinders 1, 2, & 3 (see picture).

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Current suspects are:
- Bad battery (have noticed more drain than what should be normal, but it's been starting ok)
- Bad O2 sensor
- Bad TPS
- Bad catalytic converter

Anyone with a solid lead would be greatly appreciated!

 

ive had similar problems, take your coils and spark plugs out and look into the piston and see if its wet that will confirm you are running rich which is injector related either they have gone bad or are the incorrect rating, as for the misfire mine was due to a blocked PCV system , also make 100% sure there are no cracked pipes anywhere vacuum leaks are a nightmare on these cars, limp mode for me was throttle body related after replacing it the car no longer died also made sure all your vacuum lines to the turbo are correct their should be a diagram on the underside of your hood

hope this helps

Chris

 

Thank you for the recommendation. Turns out the clamp between the intercooler hose and the throttle body had slipped and the plastic hose popped off. I was feeling around for the throttle position sensor plug when I discovered the problem.

After that was fixed, the radiator blew, so I got to demolish the front end of the car and put in a new one. Luckily, the local shop was able to find one for $200 (new). This gave me an opportunity though to completely remove the hose, inspect, and re-secure it with some space to work in.