My grandsons 850 wagon flunked emissions. The EGR valve and air injector were replaced. This involved removing the battery and doing a drive cycle reset. I also had to replace the check engine bulb in the cluster. The system has not reset after 200+ miles of both slow speed and highway driving with 3 hour cool down periods between cycles of about 30-50 miles each. The tank level has been kept between 1/4 and 3/4 full at all times. No codes show when checked at my inspection station. The car will not pass emissions because 6 channels are open. A car of this age is only allowed 2 open channels in NH.
Could the burned check engine lamp bulb be a clue that something dark is lurking here?

BTW is it a practice for Volvo people to open the output hose on the air injector to blow accumulated water out of the system periodically?

 

Ray here.

Just drove up to the Volvo dealer in Manchester NH. One of the service writers told me this model of Volvo can take up to 5-700 miles to reset.

These guys, Merrimack St. Garage in Manchester NH have been a great help to me in working on this problem. They also manufactured the Jomar sportscar at this ocation in the late 50s-early 60s. The have some examples on display.

 

Didn't see the year hiding up there in the corner

You can also get free code reading done at Oreilly or Autozone as you have an OBD II port by your shifter.

Check engine light bulb being pulled out or replaced with burnt out bulb by a previous owner to hide something is a dark indicator but just having a burnt out bulb if you know it was working before is just that, only a bad bulb.

You should add some basic info to your "signature" in the "user CP". That way we would know wagon/sedan, engine, turbo or not, manual or auto trans. Cuts down on a lot of questions.