That's interesting because im going throught the same problem. I have a 97 Maxima and the engine light came on. I had it scanned and the code was P1441 which means "Vacuum cut bypass valve or ciruit fault".I dont know what that is. I need help with figuring this out too. try taking out the egr valve and cleaning it really good with break cleaner also change the gasket it's like 3 bucks unhook your battery for 10 minutes to let the computer reset itself after that drive for about 20-30 minutes to let the computer relearn the car then take it to autozone or checkers and use their free code reader to see if it is still reading that code if so change the egr valve all together with. Check the connection between EGR valve tube and the engine. The tube can be easily clogged by carbon deposit from the exhausted gas. At least that is what happened to my 96 maxima. The tube is kind of difficult to reach because it is on the back of the engine, opposite to the firewall.
Bad gas mileage. Car studders or shuts off at stop or turns. Black smoke.
in the air filter cover
it could be your mass air flow sensor
Trouble code P0400 means:Exhaust gas recirculation flow malfunction
Trouble code P0400 means:Exhaust gas recirculation flow malfunction
Trouble code P0400 means:Exhaust gas recirculation flow malfunction
Trouble code P0100 means:Mass or volume air flow circuit malfunction
Trouble code P0400 means:Exhaust gas recirculation flow malfunction
Trouble code P0400 means:Exhaust gas recirculation-flow malfunction
No it will not run with out it, It HAS to have it.
The mass airflow sensor is installed in the air intake duct If you look at the air filter box it is just to the left on the arm of the box
EGR Flow malfunction