Q&A

Most likely your catalytic converter is becoming inefficient due to mileage age or both. O2 sensors will also become inifficient as well due to the same reason. Both of these components will not pose a drivability concern but will need to be addressed. The reason it won't set the monitor is because it is operating on the "edge" of failure. If you replace the sensors and converter the monitors will set without issue. Due to the convertor needing replacement and the overlapping labor involved with the sensors. You should replace both. You also need to be sure the exhaust system before the converter is free from any type of leaks.

Ken Stashik
Service Manager
Rusnak Pasadena Volvo

GENERALLY THE CAR NEEDS TO BE AT A DESIRED TEMP AND SPEED FOR THE COMP TO RUN THIS TEST ALSO GAS LEVEL SHOULD BE NEAR FULL AND FOR THE COMP TO RUN THIS TEST U MAY NEED TO DRIVE FOR ABOUT 30 MINS IF NONE OF THIS WORKS YEA REPLACE THE O2 SENSOR ITS EASY TO DO YOURSELF WHEN THE CAR IS COLD SO U DONT BURN URSELF IT TAKES A 7/8 WRENCH AND A JACK FOLLOW THE WIRE TO WHERE ITS CLIPED IN AND DISCONNECT IT AND UNSCREW FROM EXAUST. IF YOU NEED THIS TO BE DONE YOU CAN REACH ME AT 714-496-2286
MOBILE AUTO REPAIR PROS
WAYNE THE MECHANIC
HAVE A GOOD DAY

Ken from Rusnak pretty much nailed it. When operating properly, just driving the car a couple of times from a cold start for 15-20 minutes each time will set the monitors. This is not true for the earlier Volvos, but by 2002 the drive cycle was pretty much just driving the car for a bit.
Without seeing the tailpipe numbers from a smog test, it is hard to say if you have a bad cat, or bad sensors, or both.

Readiness on a 04' XC90 isn't as bad as the older 98 XC70, start by: Start the engine and accelerate to approximately 1500-2000 rpm to warm it up, then drive for 5 minutes at 45-50mph on a stretch of freeway (about 5-10 miles on clear road, maybe more) Stop the vehicle and remain at idle in drive for 1 minute. Resume another 45-50mph and drive for 5-10 minutes lastly stop the vehicle and remain at idle in drive for 60 seconds. Park the vehicle and turn off the engine. Repeat again if you want to ensure proper readiness. It might take a few tries. Last tip: Make sure you TURN OFF THE A/C and not on Defrost mode, it will not perform the readiness drive cycle if your A/C is cycling. Good luck, -Sam

Instead of guessing with exspensive components, you really need to have your vehicle properly diagnosed. Your problem could be a simple air leak.

Hi Bosslady
If hanging on to your hard earned money is your goal then you diffently want to stay away from the dealer, Especialy the one in Pasadena that wants sell you sensors and catalytic converters. He doesn't even know what fault codes you have.