On Saturday when driving home CHECK ENGINE light came one in my '98 S90. I immediately stopped and visually checked major systems. Everything was normal. Since I was just 1 mile from home, I drove safely to my garage. I did not notice anything different in the performance. Since I recently bought Alex Peper's Vehicle Explorer OBD-II "tool", I quickly connected to my car's ECU and got the following reading:

Received from $17 (Engine Controller): P0442 - Evaporator Emission Control Leak Detected (Small Leak)

I checked the code against the Volvo pocket data booklet and it said "442 - Airpump Relay, signal missing or faulty". I don't think that the description I got from the Alex Peper's tool is correct. I belive my Volvo booklet. I cleared the code and drove the car around the block. CHECK ENGINE light did not come on.

So, anybody else had experience with 442? I understand that this is related to that black thing on the left side of the engine's block called PAIR, "Pulsed Secondary Air Injection System". From what I read in the manual, I don't thing it is a critical component. (Am I wrong?) I am going to check the PAIR relay tonight, but my guess it is going to be Ok since the CHECK ENGINE light did not return after I cleared the code. I tend to believe this was an intermittent problem. Anyone got any ideas on how to troubleshoot this?

Thank,
Raphael