Check engine light on my 95 - EGR insufficient flow?
A few years ago I replaced the EGR valve on my 95 4-banger auto because the check engine light came on with the code for "EGR valve insufficient flow". Shortly after that my check engine light burned out behind the dash so I never bothered to test it again since the mileage was so high on my truck (just under 200,000 miles at the time). Anyway, since then I've never been able to get better than 19-22 mpg highway when originally I always got between 25-27.
I'm bringing this up because for the hell of it I borrowed my brother's check engine light tester Friday night and it still shows the same code for "EGR valve insufficient flow" which means the new valve I had installed in 08 obviously didn't fix the problem. What else could it be? I'm at 238,000 miles as we speak and I'd love to get that 25 mpg back again.