rgorke
Dedicated LVC Member
I began getting a periodic P0401 EGR Insufficient Flow code in my 2004 LS V8. I pulled the EGR valve and cleaned the insides with carb cleaner and reinstalled. Fortunately I had an extra metal gasket. Of course I dropped one gasket and it slide under the intake manifold. I tried to retrieve it with one of those long grabber snake things and managed to get it securely lodged somewhere in the bowels under the intake. The other "of course" is that the vacuum harness between the EGR, throttle body and fuel pressure sensor cracked in several places during removal. I was able to reconstruct the harness with vacuum line from the local NAPA.
Once i got the EGR reinstalled, I then got a P0403 and P0108 code. The fix was disconnecting the EGR electrical connector and cleaning with Deoxit cleaner and reconnecting. I'm not quite sure if it was the Deoxit or I didn't have the connector fully seated but now no codes after 300 miles of driving. I do have a new EGR coming from Rockauto. Debating whether to put the new one in or return it.
Now to the cooling system...when I removed the EGR, I had a clean line of sight to the 9N499 neck that had coolant stains on the base. I cleaned off the coolant stain and after I drove the aforementioned 300 miles, I can see a line of seepage coming from the under side of the 9N499 neck starting at where it connects to the 8548 main crossover pipe body. I did a full cooling system replace about 4 years ago including all the plastic parts, thermostat, hoses, degas, etc. I am thinking the O ring between the 9n499 and the main crossover body has failed and/or is not seated properly. I'll start by replacing the O ring rather than replacing both the 9N499 and crossover pipe.
The car is NOT overheating. On the freeway it stays under 205 (which is the norm) and occasionally up to 210 sitting in traffic with the AC blowing.
Thoughts on if replacing just the O ring is a fools errand. I am one of the first to advise a full replacement of cooling system parts but since it has only been 4 years, I'm not sure that is warranted.
Once i got the EGR reinstalled, I then got a P0403 and P0108 code. The fix was disconnecting the EGR electrical connector and cleaning with Deoxit cleaner and reconnecting. I'm not quite sure if it was the Deoxit or I didn't have the connector fully seated but now no codes after 300 miles of driving. I do have a new EGR coming from Rockauto. Debating whether to put the new one in or return it.
Now to the cooling system...when I removed the EGR, I had a clean line of sight to the 9N499 neck that had coolant stains on the base. I cleaned off the coolant stain and after I drove the aforementioned 300 miles, I can see a line of seepage coming from the under side of the 9N499 neck starting at where it connects to the 8548 main crossover pipe body. I did a full cooling system replace about 4 years ago including all the plastic parts, thermostat, hoses, degas, etc. I am thinking the O ring between the 9n499 and the main crossover body has failed and/or is not seated properly. I'll start by replacing the O ring rather than replacing both the 9N499 and crossover pipe.
The car is NOT overheating. On the freeway it stays under 205 (which is the norm) and occasionally up to 210 sitting in traffic with the AC blowing.
Thoughts on if replacing just the O ring is a fools errand. I am one of the first to advise a full replacement of cooling system parts but since it has only been 4 years, I'm not sure that is warranted.