typeSH714

okay i have this 99 prelude sh with the CEL on. i ran the diagnostic and it read p0401 which means "EGR flow insufficient." i've already tried cleaning off all the carbon build-up in the egr valve. i unbolted it, sprayed the inside with some carb cleaner, and used an air compressor to clean out the ports, then i replaced the gasket and bolted it down. i cleared the code and after driving a few miles, the CEL returns.

can someone please tell me how to fix this problem?!!

ive heard of many cases of people replacing the egr valve only to have the CEL come on soon after. i did a little research and found out that it could be my DPFE sensor, but i have no idea where this sensor is located or how to change it.

please help me!!


Modified by typeSH714 at 9:22 PM 3/22/2006

typeSH714

ok i did some further research and thought maybe my egr ports were still clogged. so i decided to pour some seafoam into my egr ports, and drive the car around until the exhaust stopped spewing white smoke. then i reset the ecu

after about 30 miles of driving, the cel comes on once again. this is really frustrating, i wanna solve this problem once and for all.

well, i did another seafoam treatment thinking that there may be some more carbon build-up clogging up the ports.

can someone give me another way to clean the EGR ports thoroughly?