Hi- I recently illuminated the check engine light on my '94 850 n.a, car had no driveability issues, idles smoothly, and gets about 30 mph. Car was warming up in my driveway, light came on. I checked the codes, only 1-5-4 on port 6 came up, for EGR system flow too high. I cleared the code and drove the car for about 1.5 days, then the light came back. I dismantled the airbox and other things in the area of the EGR valve to get a good look, could not see any signs of bad vacuum elbows or lines, can't hear a vacuum leak, and the car idles fine, has no apparent signs of anything wrong. Could the diaphragm in the valve itself have went bad? Thanks for any advice- Brett

Brett -

I also have a 94 850 (N/A, 147K) that got a 1-5-4 in port 6. I continued to clear the code a number of times, and it would come back on anywhere from 2-3 days later. Like you, the car ran fine and there was no sign of any vacuum leaks. Finally, after another time of clearing the code, it didn't come back on. I've gone probably 3 weeks now and it hasn't returned. The car also recently passed emission inspection with no problem.

Let us know what you find out if anything.

Regards,
Steve Kammerer

As I understand it the EGR itself can get clogged up and needs to be cleaned or replaced. I just had done on my 94 855 by my indy - $79 to get in and clean everything up, including removing & testing EGR. I was told that sometime the hole to the EGR can be so blocked they have to drill it out.

So you might just be gunked up.

have '94 850 with 174,000. same code came up a week ago.
some people said new gas cap.
but i very closely checked all vacuum hose elbows. found two that were bad. one was soft to the touch (replaced)and other one (split)was underneath the fuel rail. so far no light. ipd sells elbow packs but i checked their website only to see the picture of where some of the elbows are. used some left over evap hoses for the fixes.