My '91 has been tripping MIL code 12. It's got 225,000 miles. I've replaced the EGR control valve and CV assy. EGR valve replacement is on the way. While looking thru the maintenance manual today I discovered the EGR port and decided to remove and clean it. Pretty gunked up. Now I'm wondering if I've wasted time and cash on new parts when all I needed to do is clean the porting. Anyone got any advice before I pull off the intake manifold?
Code 12
- Thread starter Dr. JL
- Start date
Took the intake manifold off today. No issues. Able to disconnect the throttle body and not deal with coolant. Took the manifold apart and cleaned the EGR ports. From what I could tell, 4 of 6 ports were completely clogged. Had to fabricate port cleaners and use pressurized air and solvent to clear out the carbon gunk. Hopefully, the port cleaning and new EGR valve will cure the CEL. Not sure if this cleaning has been done before but, if not the entire IM was pretty clean. I'd say about 1 mm of oil in the magnesium lower casting. Honda makes awesome vehicles!
The EGR valve movement is monitored and if it does not move as commanded you get the code. The ECU has no way of telling if the passage ways are clear or blocked so its good you cleaned them but its not the cause of the code.
Thanks for the words Briank. I'm hopeful the new parts and port cleaning will protect the engine. A thread on this site mentioned Acura Legend head gasket failures due to EGR component failures. Just tired of spending time and money chasing down the cure to this fault code.
