Hi,
I have a 1996 Chevy Lumna sedan with 130.000 miles. The engine light is on and my scanner reades P0401. All othere checks are ok.
The car runs fine. Some causes could be excessive backpressure. How do I check for that? Any way I can check the EGR valve incase that is the problem? A new one cost $160 and it is too expensive to take the shotgun approach. Any ideas would be appreciated. The car is due for it's state inspection in August.
Thanks, Ed