I just had my local indy overhaul the pcv system in my 94 850T (new oil trap, hoses, the works). But I did not have him install a new EGR valve while he was doing the job. It's a $180 part through FCPGroton so I figured I would leave it alone since it had not been giving me any problems. After he got everything put back together, the car is tripping a 2-4-1 fault code which is "faulty EGR flow". The car runs great and if it weren't for the annoying Check Engine light I would just forget about it. Anybody had a similar situation occur? If I bite the bullet and replace the EGR valve, will that fix the problem? Thanks for the help.

You know, I'm dealing with this same issue right now. I've got a 241 as well. So far I've been dealing with the intake system because it was chock full of leaks; the dipstick was leaking as well as replacing one hose and elbow. My mechanic managed to clamp one leak (which I think did the trick) and repositioned a hose to fix another. It looked like the leaks were sealed, however I'm still getting the check engine light when I rev up just a bit over moderate acceleration, as well as when I start it up for the first time in the morning, etc. I am hoping it's not the EGR valve or regulator as they're both about 160 bucks and I'm still just a student here - that's alot of money to me. I'm really interested to see how/what you do - and I'll let you know how I do as well, we could very possibly have the exact same problem.

David
--
1995 850 Sedan, Naturally Aspirated, 142k mi

If the other suggestion doesn't work, you might try disconnecting the battery (make sure you have your radio code) for several minutes and let your ECU reset itself. Problem could be that it's just not used to the new way the system breaths.
--
1998 S70 T5 Emarald Green Metallic (125K), 2004 V70 2.5T Ruby Red (45K), Previous Owner of Black '94 850 Turbo Wagon (Sold at 140K and miss her). My cars have been running so well lately they've got me worried.

Try cleaning the throttle body first. There is a little hole in the bottom of the thottle body going to the EGR system that very likely is clogged. I've even heard of people having to drill out the hole.

Hopefully that is all it is. And there are actually 2 parts to the EGR system - and both cost in the $150-$180 range....

That said - had the same problem with my 94 850 and did cleaning, valve and then EGR solenoid. However, if you can find used (which mine where) much cheaper and so far just as good.