Got the 'Lambda Sond ' warning lamp on for the first time ever. Pulled code 241 which is "EGR - low flow through system". I posted this last week and everyone suggested pulling the valve out and cleaning it. However today after talking to both the dealership and my independent Volvo tech they had different opinions. First the parts guy at the dealership said he has never sold an EGR valve or valve gaskets and throttle body gaskets as required by Bay 13 instructions. My Volvo tech says he has never had to replace an EGR valve on a 850 and that it isn't the EGR valve but the pipe from the intake manifold that gets fouled up not allowing the valve to work (makes sense). They are quoting me two hours labor only (no parts) to take apart and clean. What pipe exactly is he talking about and where is it located? TIA

I've had a few experiences with 850 EGR valves and although the OEM service manual will get one to properly diagnose problems with the system such as testing vacuum devices, the most common problem I've seen with high mileage 850s is that the hole in the intake manifold simply clogs with an oil/carbon type debris and it becomes very solid.
To access that, the pipe must be untreaded from the valve, the throttle base removed and then remove the EGR valve completely (SAVE the gasket or replace).
With the EGR valve and throttle base removed, if that hole is clogged as I'm suspecting, you'll see it and it'll be obvious. Use a drill bit, screwdriver or sharpe object to open that hole up and your problem should be cured.

Thankyou Fred for a the clear explanation. It pretty much sounds like the same response I got from my Volvo tech. I got "in there" the other night and cleaned the throttle body and flame trap while I was at it. With poor lighting and frigid temperatures in my garage, I decided that this is one job I'm going to hire out. My tech quoted me 2 - 21/2 hrs labor. I'll have the gaskets replace with new. FWIW, I did the same job years ago on my 240 and replaced all the pipes and valve with new. Much easier to work on!