A few months back, I replaced everything -- the solenoid, EGR and all the hoses, and it went away for a few months.

I even replaced the solenoid from the Air Pump recall.

Its throwing the same P0400 code all over again.

If anyone can help, I listed the Freeze Frame info from my OBD2 reader:

DTCFRZF: P0400

Fuelsys1: CL
Fuelsys2: CL
Load PCT: 7.1
ECT (F): 179
SHRTFT1 (%): 0.8
LONGFT1 (%): -0.8
SHRTFT2 (%): 0.8
LONGFT2 (%): 0.0
MAP(PSI): 6.1 ?
RPM: 1218
VSS: 21
MAF: 0.04
TP (%): 11.0


The only thing I can see as strange is the SHRTFT & LONGFT numbers are low or negligible when compared to live data.

Any help or suggestions?

Thanks,
Mike

 

may sound weird, but check for exhaust leaks, looking at the service info thats one of the things that can set the code off

this is lifted right from the service info

Suction from shop exhaust hoses can alter back pressure and may affect the operation of the EGR valve during in–stall testing. This DTC can be set by a leaking exhaust system because an exhaust leak alters back pressure. Thoroughly check the exhaust system for leaks. Refer to Section 6F, Exhaust System.
Vacuum lines should be thoroughly checked for proper routing. The vacuum source goes to the orifice side of the solenoid valve. Refer to the Vehicle Emissions Control Information label.
Using Freeze Frame and/or Failure Records data may aid in locating an intermittent condition. If the DTC cannot be duplicated, the information included in the Freeze Frame and/or Failure Records data can be useful in determining how many miles since the DTC set. The Fail Counter and Pass Counter can also be used to determine how many ignition cycles the diagnostic reported a pass and/or a fail. Operate vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature etc.) that were noted. This will isolate when the DTC failed.
A leaking EGR valve pipe assembly will cause an exhaust leak and can reduce EGR flow volume. Refer to Section 6A, Engine On–Vehicle Service if this condition is noted.